The range of this species is primarily in the Gulf of Mexico where it occurs on marshes in Mississippi and Texas, USA, in a lagoon in Mexico, and rarely on the Mississippi shelf. It has also been recorded as rare infaunal (2–4  cm) in North Carolina marshes, USA (Culver & Horton, 2005).

The main environment is deep sea and shelf (Fig. 4). In the Weddell Sea it is infaunal to 3.5 cm (Mackensen & Douglas, 1989). The occurrences in fjord and marginal marine may be incorrect identifications. It occurs where the mean sea floor organic C flux is 7 g  m² a^–1 (Altenbach et al., 1999).

Two distinctive features of this species are the circular cross-section of the uniserial part and its habit of incorporating dark sedimentary particles into its wall. Although it was first described from a marsh and has since been recorded in another marsh (Arcachon, France, Le Campion, 1970, as A. agglutinans) the main occurrences are in marginal marine settings from shallow subtidal to low intertidal (Alve & Murray, 1994). It is restricted to the NE Atlantic (Fig. 5). The range of salinity tolerated in marginal marine southern Scandinavia is 15–29 (Alve & Murray, 1999).

Most occurrences are marginal marine or marsh, mainly in the West Atlantic but it is also present in the Pacific (Fig. 6). There are minor occurrences on the shelf off North Carolina and Texas, USA. It occurs infaunally to 8 cm off North Carolina (Lueck & Snyder, 1997).

Most occurrences are marsh but it is also present on the shelf off North Carolina and Texas, USA, and there are a few records from marginal marine settings (Fig. 7). It is absent from the East Atlantic and the Indian Ocean. It is infaunal down to 8 cm on the shelf (Murosky & Snyder, 1994) and to 10 cm in a marsh (Steineck & Bergstein, 1979).

With the exception of a single record from the shelf off Cape Hatteras this is known exclusively from the deep sea of the Atlantic and Pacific oceans (Fig. 8).

This species has a very restricted distribution with the majority of occurrences in marginal marine, some fjord, with rare records in marsh and shelf. In southern Scandinavian marginal marine environments it is common only on sediments with <20% mud, a median diameter of medium to fine sand, and low total organic carbon (TOC, 0.2–0.7%) (Alve & Murray, 1999). It is confined to the NE Atlantic and Baltic Sea (Fig. 9).

This species occurs in the Atlantic, Mediterranean and Pacific oceans (Fig. 10). It is abundant in marsh and marginal marine environments with a few occurrences on the shelf. In some instances it forms monospecific assemblages (brackish to hypersaline marsh, Texas, USA, S 2–42 (Phleger, 1966) and very brackish lagoon, S 0–10, in Mexico (Phleger & Lankford, 1978)). The range of salinity tolerated in marginal marine southern Scandinavia is 15–27 (Alve & Murray, 1999). It has been shown to be infaunal (0–10 cm) in North Carolina marshes, USA (Culver & Horton, 2005). In the NE Atlantic and Mediterranean it is much less widespread in marginal marine environments than it is in the West Atlantic and Gulf of Mexico. In the Adriatic it shows a high correlation with the density of sea grass and also with specific diatoms as a food resource but rejects blue-green algae (Hohenegger et al., 1989). In the Gulf of Mexico it extends on to the shelf adjacent to the Mississippi delta. It is a detritivore feeding on bacteria (Matera & Lee, 1972).

A dominantly marsh species it is also found in marginal marine lagoons especially on the western side of the North Atlantic. Occurrences in the NE Atlantic are restricted to France; it is infrequent in South America and the Pacific (Fig. 11). Infaunal down to 2 cm in New England marshes (Saffert & Thomas, 1998), and in Georgia, USA, it is patchy in surface sediments of the low marsh but infaunal down to 30 cm in moist high marsh sediments (Goldstein & Harben, 1993). It is found infaunal down to 50 cm in an Australian mangal (Berkeley et al., 2008).

There has been some taxonomic confusion surrounding this species. It is recorded as Trochammina macrescens f. macrescens by Scott and as T. macrescens type A by De Rijk & Troelstra (1999) (see Alve & Murray, 1999). This is one of the few species found exclusively in a single environment, highest marsh: in the NE Atlantic from southern Scandinavia to southern England, West Atlantic from Canada (where it reaches it greatest abundance) to the northern Gulf of Mexico, then a gap past Brazil to Argentina. In the Pacific Ocean it is known from California, USA, and Japan (Fig. 12). It is epifaunal and associated with damp, rotting leaf litter (Alve & Murray, 1999) and is an extremely low-salinity euryhaline species.

The Mesozoic genus Verneuilina d’Orbigny, 1839, was used by nineteenth- and early twentieth-century workers for triserial forms that have now been assigned to other genera, such as Eggerella and Eggerelloides. Loeblich & Tappan (1987) place Verneuilina in the Superfamily Verneuilinacea and Eggerella and Eggerelloides in the Textulariacea. In both superfamilies the wall is said to be canaliculate yet this is not true for all species assigned to Eggerella or for Eggerelloides. However, when Cushman erected the genus Eggerella he described the wall as having calcareous cement but made no mention of canaliculae.

The type species of Eggerella is Verneuilina bradyi Cushman, 1911. This is a deep-sea form with a canaliculate wall and calcareous cement. This is not the case for Eggerella advena so the reason for placing the species advena in this genus is not clear but perhaps Cushman did not consider the nature of the cement to be a significant taxonomic feature. Eggerelloides was erected by Haynes (1973) with the type species Bulimina scabra Williamson, 1858. Like Eggerella advena it has an agglutinated wall with organic cement. The aperture of the former is a low arch at the base of the apertural face, whereas that of Eggerelloides is a high loop-shaped slit extending up the apertural face.

Cushman (1922, p. 57) gave as his description: ‘Variety differing from the typical in the smaller size and more slender form’. From comments on p. 56 it is clear that ‘the typical’ is what is now called Eggerelloides scaber. Of the 215 occurrences along the eastern seaboard of North America, 57% are from marginal marine settings (mainly Long Island Sound, Buzas, 1965), 37% are on the shelf and the remainder are from marsh and fjord. These are all from cool waters derived from the north. The salinity in Long Island Sound is 25–29 and on the open shelf it is 32–35. Buzas (1965) considered that the abundance of E. advena is probably related to food supply. There are only 5 occurrences in the Caribbean (Jamaica, Puerto Rico) and the identification of these may not be correct.

Along the Arctic, Atlantic and Mediterranean coasts of Europe E. advena has been reported mainly from the shelf (97% of 168 occurrences) (Fig. 13). It is likely that some of the identifications are suspect. Scott et al. (2003) recorded it in the Celtic Sea (30 samples). However, the author has never seen it there although Eggerelloides scaber is present. Daniels (1970) separated E. advena from E. scaber in the Adriatic Sea on the basis that the former was mainly half the size of the latter. Since both species were recorded in 115 samples it may be that they are really one and that is likely to be E. scaber with the juveniles being reported as advena. Together these two instances account for 86% of the 168 occurrences. The records from the Arctic may be authentic.

On the Pacific seaboard of North America there are 186 occurrences, 67% of which are from borderland basins (which extend down to >1000 m), 25% from shelf and the remainder from marsh and marginal marine. Most of the basin occurrences are those of Uchio (1960), who erected the species E. scrippsi on the basis that the wall is composed of finer particles and is smoother than that of E. advena. Nevertheless, he had difficulty separating the two species. Here they are both considered as E. advena.

There are 66 records from Japan. Of these, 26 are from heavily polluted Osaka Bay which has restricted connections with the open sea (Tsujimoto et al., 2006). Over the past 50 years there has been a major faunal change which the authors attribute to the increase in pollution leading to hypoxia and anoxia. However, this species is abundant in Ishikari Bay which is open to the sea and was not reported as polluted or hypoxic at the time of sampling (Ikeya, 1970).

This appears to be a detritivore (Murray, 1991) and to tolerate hypoxic conditions in areas subject to pollution. It is highly mobile (Schafer & Young, 1977) and was a pioneer species in recolonizing sediment dumped from dredging in Canada (Schafer, 1982). It is infaunal down to 10 cm off North Carolina (Murosky & Snyder, 1994).

This distinctive small, elongate species was first recorded by Höglund (1947) in Gullmar fjord, Sweden as Verneuilina advena Cushman. It has an organic-cemented wall so does not truly fit in Eggerella. Rare living occurrences are confined to Hardangerfjord, Norway, the Skagerrak and the shelf west of Scotland. In a two-year experiment, where the fauna was deprived of fresh phytodetritus, it increased in abundance, indicating that it feeds on degraded food (Alve, 2010).

First described from Gullmar Fjord, Sweden, this species was originally confused with E. scaber. Where the two species co-occur care has to be taken to separate them; medius generally has a coarse finish to the wall and is slightly less pointed at the initial end than scaber. Eggerelloides medius lives primarily on the shelf (74%) and in fjords in Scandinavia (24%) with rare occurrences in deeper water (Fig. 14). The shelf occurrences extend from the northern North Sea and Skagerrak to southern England and to the west of Scotland where core records show it down to 3 cm (the limit of sampling) (Murray, 2003). There are rare records from the deep sea from west Norway down to 856 m (Mackensen, 1985). Eggerelloides medius is a cool temperate species. It is confined to water depths >90 m where some mud is present in the sediment (Murray & Alve, 2000b). In a fjord (Alve & Nagy, 1986), in the North Sea (Klitgaard-Kristensen & Sejrup, 1996) and on the shelf off Scotland (Murray, 2003) it shows a correlation with % TOC and fine sediment fraction. In a two-year experiment, where the fauna was deprived of fresh phytodetritus, it decreased in abundance, indicating a need for fresh food (Alve, 2010).

Particularly common in the NE Atlantic but absent from the West Atlantic (Fig. 15). It occurs in marginal marine, fjord, shelf and deep sea but is most abundant on the shelf, although the single highest abundance is from Oslo fjord. The range of salinity tolerated in marginal marine southern Scandinavia is 19–28 (Alve & Murray, 1999). It requires a salinity of at least 24 for most of the year in order to flourish and the optimum is 29–35 (Lutze et al., 1983). It may have been more common in the western Baltic in the past but is now found only in higher salinity areas, such as deeper Kiel Bight (Polovodova et al., 2009). It tolerates a broad range of temperature but the optimum may be 15–20°C (Murray, 1968). Although it tolerates oxygen levels of <0.5 ml l^–1 it took more than one year for it to colonize sediments recovering from a prolonged period of anoxia (Alve, 1995a). In the Adriatic Sea it occurs in shallow water where there is periodic oxygen deficiency (Donnici & Serandrei Barbero, 2002). In Drammensfjord, Norway, it is most abundant in the upper part of transitional water masses due to a combination of salinity conditions, increased organic flux and depleted oxygen (Alve, 1990). However, Schönfeld (2001) considers it to be an oxic species based on measurements of pore water oxygen. In the Celtic Sea it correlates with high sand content (Scott et al., 2003). It is tolerant of heavy metal pollution (Frontalini & Coccioni, 2008). In the deep sea it extends down to a maximum of 1500 m in the Gulf of Guinea and, in submarine canyons, down to 920 m in the Gulf of Lions and 3097 m in Nazare canyon off Portugal. Some of the deep-sea occurrences might be misidentified juveniles of Liebusella goesi (Alve & Goldstein, 2010). It is also reported from Japan and the Indian Ocean where it is named E. scaber australis. It is generally infaunal: in the North Sea down to 25 cm with peak values at 0–7 cm (Moodley, 1990) and in the Adriatic down to 7 cm but it occurs predominantly in the top cm where it may reproduce (Barmawidjaja et al., 1992). It is also epiphytic on seagrass (Debenay, 2000; Semeniuk, 2001). It sometimes has green protoplasm (suggesting herbivory) but Alve & Goldstein (2010) conclude that it is an omnivore.

This is primarily a marginal marine form but it also occurs on marsh (where it reaches it highest abundance) and shelf. It is absent from the East Atlantic and Pacific. It is present in the warmer parts of the West Atlantic and the Indian Ocean (Fig. 16).

On the Pacific margin of North America it occurs on marshes and in marginal marine environments, while off Japan it is found on the shelf. The only record from the Atlantic is from the shelf in the Caribbean (Fig. 17). The single record from the deep sea at 537 m in the Scotia Sea is almost certainly a misidentification.

The records span all environments from marsh to deep sea but this is essentially a shelf and deep-sea form (Fig. 18). It is present on shelves in the Arctic, on both sides of the North Atlantic, off California, USA, and Japan. The deep sea records are from the Atlantic Ocean, Scotia Sea and Southern Ocean, Japan and South China Sea. Most abundances are very low and the only location where it exceeds 10% is a single sample from a lagoon in Brazil (Duleba & Debenay, 2003). It occurs where the mean sea floor organic C flux is 7–9 g m² a^–1 (Altenbach et al., 1999).

Although often considered to be a deep-sea form, H. bradyi also occurs commonly on the shelf and more rarely in Norwegian fjords (where it has its highest mean value). Most occurrences are in the East Atlantic (Fig. 19) but it also occurs in the Pacific, Indian and Southern oceans. In a two-year experiment, where the fauna was deprived of fresh phytodetritus, it increased in abundance, indicating that it feeds on degraded food (Alve, 2010).

The common shallow-water species are Haplophragmoides bonplandi, H. manilaensis, H. subinvolutum and H. wilberti. All these forms are morphologically variable so it is uncertain whether there are truly as many species as have been named. Alve & Murray (1999) noted that their H. wilberti included forms regarded as H. manilaensis by D.B. Scott (pers. comm.). These four Haplophragmoides species are typical marsh forms (93% of occurrences) although there are sparse records in marginal marine and shelf settings (Fig. 20). They occur in East and West Atlantic and Pacific oceans. Haplophragmoides wilberti is recorded widely present elsewhere; H. bonplandi is found in Canada and North Carolina, USA; H. manilaensis in Portugal, eastern USA, Gulf of Mexico, Brazil and Japan; H. subinvolutum Texas, USA, and Pacific USA. Haplophragmoides manilaensis is found down to 2 cm in New England marshes (Saffert & Thomas, 1998). The range of salinity tolerated by H. wilberti in marginal marine southern Scandinavia is 10–27 (Alve & Murray, 1999).

Although a typical marsh species, J. macrescens also occurs in adjacent intertidal marginal marine environments. In the NE Atlantic marshes it extends from southern Scandinavia to Portugal and also into the Eastern Mediterranean (Greece, Italy: Scott et al., 1979). In the West Atlantic it occurs from Canada to the northern Gulf of Mexico; there is a gap until it reoccurs in Brazil and Argentina. Pacific occurrences are from Canada to Baja California, also the Banda Sea and New Zealand (Fig. 21). The marginal marine occurrences parallel those of the marshes but in lower abundance and there is an additional record from the South China Sea. The only shelf occurrence is off the Mississippi delta in the Gulf of Mexico. It is considered to be a generalist with a mode of life ranging from epiphytal on decaying phanerogam leaf debris (Matera & Lee, 1972; Alve & Murray, 1999) to infaunal down to 30 cm (Ozarko et al., 1997). It probably feeds on bacteria and decay products from the leaves. The range of salinity tolerated in marginal marine southern Scandinavia is 10–28 (Alve & Murray, 1999).

It is known from fjords, where it occurs in marine waters below the halocline (Alve & Nagy, 1986) and especially on the continental shelf and shelf deeps (Skagerrak, Alve & Murray, 1997) but its highest abundance is at 405 m on the slope near Dakar off NW Africa (Lutze, 1980) (Fig. 22).

Extremely euryhaline tolerating salinities of <1–35 but there is no correlation between its abundance and salinity (De Rijk, 1995) although Debenay et al. (2002; 2004) found it more abundant in low salinity areas in French Guiana. It is epifaunal to slightly infaunal (Ozarko et al., 1997; Saffert & Thomas, 1998) but Tobin et al. (2005) found it down to 20 cm in a Canadian marsh and to 30 cm in North Carolina, USA. It is epiphytic on filamentous algae on a marsh in southern England (Alve & Murray, 1999) and in the Baltic it makes up to 50% of epiphytic assemblages on algae (Wefer, 1976). In an Australian mangal it is infaunal to 40 cm (Berkeley et al, 2008). This widespread species is found abundantly in marsh and marginal marine and occasionally in fjord and shelf environments in the Atlantic and Pacific oceans (Fig. 23). The upper salinity limit is 25 (Alve, 1995) although the range in marginal marine southern Scandinavia is 10–29 and the maximum water depth is 2 m (Alve & Murray, 1999). Under experimental conditions using material from Georgia, USA, with varying temperature (12 and 22°C) and salinity (12, 22, 36) it grew at all salinities but was most abundant at salinity 12 and it did least well at 12°C (Goldstein & Alve, 2011). However, in Canada this is considered a cool tolerant species (Scott & Medioli, 1980) so Goldstein & Alve (2011) suggest that it may be a morphospecies complex of cryptic species with different environmental requirements. The US and Canadian representatives also show genetic differences.

This species is confined to the NE Atlantic with a rare occurrence in the Mediterranean (Fig. 24). It is mainly present in marginal marine environments but also occurs on marsh, fjord and shelf. It probably feeds on debris from higher plants and green algae (Alve & Murray, 1999) and the green pigment may indicate either symbiosis with diatoms or their chloroplasts (Knight & Mantoura, 1985). The optimum temperature may be 15–20°C (Murray, 1968). The range of salinity tolerated in marginal marine southern Scandinavia is 15–28 (Alve & Murray, 1999).

The type specimens come from the mouth of the Para River, Brazil. It has inflated chambers so the periphery is lobulate rather than smooth as in R. moniliformis.

By contrast with the latter, R. nana is common in the West Atlantic (sometimes on marsh/mangal but typically marginal marine) from Canada to Brazil (Fig. 25) and likewise along the Pacific seaboard of North America and with 4 records from South Africa in the Indian Ocean. On the eastern side of the Atlantic it is rare in marshes in northern Spain and present on the shelf in Biscay and off the Ebro in the Mediterranean. In the Adriatic it is restricted to the top 4 cm (Barmawidjaja et al., 1992).

This primarily marsh/mangal species is found from North Carolina, USA, to French Guiana with marginal marine occurrences in Tobago and Brazil (Fig. 26). It is epiphytic on mangrove tree roots in Brazil (Eichler et al., 1995; Debenay et al., 1996) yet rare in French Guiana (Debenay et al., 2002).

Sometimes recorded as T. tenuissima, this species is widespread (Arctic, Atlantic, Pacific, Indian, Southern oceans) and occurs in marsh/mangal, marginal marine, fjord, shelf and deep-sea environments (Fig. 27). In a two-year experiment, where the fauna was deprived of fresh phytodetritus, it increased in abundance, perhaps indicating a need for fresh food (Alve, 2010). In experiments using sediment collected from 320 m water depth in the Skagerrak aliquots were stored for 2 years in a cold room at the original ambient temperature of 5°C and then exposed to shallow-water conditions for 11 months; this was the only species that continued to flourish. The authors attributed this to its opportunistic lifestyle (Alve & Goldstein, 2010).

A marsh species found only in the Atlantic from southern Scandinavia to Portugal and from Canada to Brazil, with a few occurrences in marginal marine environments (Fig. 28). It is epifaunal, free or clinging to algae or infaunal down to 20 cm (Saffert & Thomas, 1998) and a herbivore or detritivore. The range of salinity tolerated in marginal marine southern Scandinavia is 20–28 (Alve & Murray, 1999).

This is the typical marsh species widely distributed throughout the Atlantic and Pacific oceans but it also occurs in marginal marine settings including in the Indian Ocean. There are single records on the shelf off Japan and the Mississippi delta and 8 occurrences in the Adriatic Sea (Fig. 29). Although found in small numbers in epiphytic communities (Matera & Lee, 1972), it is most commonly found living infaunally (e.g. Steineck & Bergstein, 1979; Langer et al., 1989; Goldstein & Harben, 1993; Ozarko et al., 1997; Saffert & Thomas, 1998; Berkeley et al., 2008). It is a herbivore or detritivore feeding on bacteria (Matera & Lee, 1972). The range of salinity tolerated in marginal marine southern Scandinavia is 10–28 (Alve & Murray, 1999). Some records of dead T. inflata from the deep sea may be misidentifications of T. subturbinatus (see Murray & Alve, 2011).

There are only 21 records of this species, from the Scotian shelf, Canada, to North Carolina, USA, with a single occurrence on the slope at 850 m off the latter.

As the name suggests this is a Pacific species with occurrences in marginal marine, shelf and deep sea along the margin of North America and off Japan (Fig. 30).

With the exception of records from a lagoon in the Gulf of Mexico (which may be a misidentification), all occurrences are from shelf or deep sea, in the Atlantic and Pacific oceans and the South China Sea. The maximum abundance is on the shelf in the Gulf of Guinea (Fig. 31). In the Gulf of Cadiz the lower and upper limits in the sediment correspond with low and high oxygen so this species is not an indicator of low oxygen conditions (Schönfeld, 2001).

Only a few species of Cornuspira have been described and the two most commonly recorded in modern sediments are C. involvens, based on material from the Tertiary of the Vienna basin, Austria (although d’Orbigny, 1839 also mentioned records from recent sediments off Cuba and Martinique) and C. planorbis, from Recent mud off Mozambique. The holotype of C. involvens is 1–2 mm in diameter while the type form illustrated for C. planorbis is a juvenile. The former seems to be microspheric and the latter megalospheric. There is taxonomic confusion surrounding these species because different workers have different views on morphological variability. Phleger & Parker (1951) noted that because of this, recorded distributions may be inaccurate. However, in view of the features of the types, it seems highly probable that C. involvens and C. planorbis are one species (discussion with Elisabeth Alve, 2011) and are treated so here.

Cornuspira involvens/planorbis is widely distributed throughout the world’s oceans, from marshes to bathyal (Fig. 32), in normal marine salinities but highly variable temperatures. Typically it ranges from zero to low abundance (rarely above 6–7%). However, there are occasional high abundances (up to 55%) which are almost certainly reproductive blooms coincident with the time of sampling. Such blooms are known from marginal marine (northern Spain, summer; Barbuda, autumn), fjord (Svalbard and southern Norway, summer), continental shelf (Scotland, summer) and deep sea. It is epiphytic off Western Australia (Semeniuk, 2001).

Confined to the Arctic Ocean and the NW European seaboard in fjords, shelf and deep sea (Fig. 33) with maximum abundance on the shelf. In the Arctic Ocean it occurs in seasonally ice-free areas and also beneath permanent ice cover (Wollenburg & Mackensen, 1998).

This genus is present (mainly as A. scalaris) in low abundance in shelf and deep-sea settings in the eastern North and tropical Atlantic Ocean and in the Mediterranean (Fig. 34). It appears to be absent from the South Atlantic. There are a few records from the deep sea in the South China Sea. It occurs where the mean sea floor organic C flux is ~40 g m² a^–1 (Altenbach et al., 1999). The range tolerated in the Gulf of Guinea is 7.4–124.2 g m² a^–1 (Altenbach et al., 2003).

Three species have living representatives (A. crepidulus, A. hyalacrulus, A. insolitus) and other references are recorded as sp.. The genus occurs only in the Atlantic Ocean in fjords, shelf seas and deep sea but only in the latter two does the mean exceed 1% and the maximum abundance is 4.2% in a Norwegian fjord. It occurs down to 4495 m in the Scotia Sea (Fig. 35).

This low latitude, warm-water species is confined to marginal marine in the Caribbean Sea and shelf in southern USA and Nicaragua (Fig. 36).

Most records are from the NE Atlantic and Mediterranean in marginal marine and shelf environments but the author also recorded it on the shelf off the USA (Fig. 37) and at 1002 m off the UK. It is epifaunal clinging to larger detrital fragments (Sturrock & Murray, 1981) or on submarine vegetation (Murray, 2006, p. 131).

Several species are known and four (echolsi, gallowayi, sidebottomi and stelligerum) are discussed below. These four species have a laterally compressed test, 8–10 chambers in the final whorl, and supplementary chamberlets arranged around the umbilici, distinct in all but A. echolsi. The types are from Recent sediments with A. echolsi and A. gallowayi from high latitudes and A. sidebottomi and A. stelligera from mid latitudes. Records for named species and including those left in open nomenclature show a distribution from marginal marine to deep sea in the Atlantic and Pacific oceans (Fig. 38) but the genus is typically present in shelf and deep sea.

The distinctive features are the compressed test with short, somewhat indistinct supplementary chambers with forward slanting apertures. It was described from the Ross Sea, Antarctica. There are no records of stained material from there but it occurs in the Scotia and Weddell seas as well as in the South Atlantic (Fig. 39).

This is the most widely distributed species in fjords from Arctic Russia and Scandinavia, shelf seas from the Arctic Ocean to the North Sea and English Channel off Europe and to the Grand Banks off Canada, and deep sea from the Arctic Ocean to the Iceland–Faroe ridge. It is also recorded on the shelf and slope off Japan (Fig. 40). Of the 151 records, 87% are of abundances <10% and the mean value for the whole dataset is 4%. The highest abundances are in fjords and shelf seas. This species favours cold to temperate conditions (the types are from Alaska).

Confined to shallow shelf seas of the Adriatic where it has a low mean abundance (1%) with a single high value (11%) which may represent a reproductive bloom.

There are 31 occurrences from shelf (Gulf of Guinea and Argentina), one from marginal marine (Tobago; probably a misidentification) and 7 from deep sea (Gulf of Guinea and South China Sea).

This readily identified widely distributed species occurs from marsh to deep sea (Fig. 41) with most occurrences in marginal marine and shelf (Table 2) and it occurs in all the oceans. High abundances are found in very shallow water along the Pacific seaboard of North America from Washington, USA, to Baja California. In the North Sea it is infaunal down to 25 cm with peak abundance in the 0–4 cm interval (Moodley, 1990). In the Norwegian Sea it extends down to 896 m.

Laevidentalina lacks the longitudinal costae of Dentalina (Loeblich & Tappan, 1987). Although numerous species of these genera have been recorded, all are generally rare with the maximum abundance (7.7%) occurring in the West Mediterranean in the shelf off Algeria (Milker et al., 2009). There are a few occurrences in marginal marine and fjord but mainly it is present in shelf and especially in deep-sea environments, in the Arctic, Atlantic, Pacific, Indian and Southern oceans (Fig. 42).

Several species have been recorded but they are all so rare that it is appropriate to consider them collectively. Apart from a single occurrence in a lagoon on Tobago, it is otherwise known from shelf (Argentina, Ross Sea), borderland basins off California, USA, and deep sea (Portugal, West Africa, Nicaragua, Scotia Sea, Weddell Sea, and Ross Sea (Fig. 43). All abundances >10% are from around Antarctica.

Thirty-six species of Fissurina have been recorded living (in one or more of 708 samples) together with Fissurina sp. in some of the same samples as well as in others, giving a total record of 1071 samples (nearly 15% of the primary dataset). Several of the minor Fissurina species occur in only one geographical area or in a single environment. However, the genus is widely distributed both geographically and environmentally (Tables 2, 3). It is, therefore, remarkable that abundances >10% are present in <1% of the samples and the mean abundance is merely 1.09%.

Fissurina marginata was interpreted to be an ectoparasite on Discorbis (Le Calvez, 1947) based on observations on live individuals but he did not conduct experiments to prove his interpretation. Other authors have noted a similar positional relationship between Fissurina and a presumed host: F. marginata on Cibicides lobatulus (Walker & Jacob), on Chlamys shells (Haward & Haynes, 1976); F. submarginata (Boomgart) on Rosalina (Collen & Newell, 1999). Haward & Haynes illustrated two F. marginata on an ‘arenaceous cover’ (i.e. feeding cyst) on Cibicides lobatulus. The protoplasm of the two seemed to be in contact but it is possible that rather than being ectoparasitic the Fissurinas were merely taking food from the feeding cyst (Haynes, pers. comm., 2011). If there is any regular association between these species then they should show some related distributions and abundances. Whereas C. lobatulus is very common in current-swept areas, F. marginata is not. The two species behave differently hydrodynamically (one much larger than the other) so this may be part of the explanation for the disparate occurrence of dead tests but it should not affect the living forms. Williamson (1848) recorded F. marginata (as Entosolenia), Rosalina globularis and ‘Polystomella crispa’ all adhering epifaunally on branching bryozoa but without any obvious association between species. The supposed ectoparasitic mode of life of F. marginata has yet to be demonstrated for other species of Fissurina even though Haynes (1981, p. 54) stated that both Fissurina and Lagena are parasitic on other foraminifera. Haynes (pers. comm., 2011) noted that the case of Lagena ‘was suggestive but not conclusive’.

Fissurina laevigata occurs in Arctic fjords and a range of environments in the North Atlantic and Mediterranean but with a single record on a marsh and only three records in the deep sea (Fig. 44) down to 3736 m in the Gulf of Guinea.

This is by far the most frequently occurring Fissurina species (401 samples) but is geographically restricted, being absent from the Arctic and Southern oceans and the Gulf of Mexico–Caribbean Sea (Fig. 45). It occurs on marshes in northern Spain (27 samples), California (32) and New Zealand (1). The majority of occurrences are in marginal marine environments (236) and shelf seas (122) and it is uncommon in the deep sea (13) where it is recorded down to 1224 m in the Norwegian Sea. It has not yet been recorded in fjords. This may reflect a preference for somewhat less cool conditions. In a 27-month time-series study of pairs of replicates from two stations in the Hamble estuary, England, it occurred 44 times in the lower intertidal station (sta. 1, close to neap low water) and only 7 times in the mid intertidal station (sta. 2, Murray & Alve, 2000a). There was great variability in standing crop, biomass and species diversity and no clear correlations with any of the measured environmental parameters, although biomass and diversity seemed to be the best guides to seasonality. Nevertheless, there must be undetected subtle differences between the two stations that make sta. 2 less attractive to F. lucida. Examination under the microscope of live individuals of the associated common species showed no physical association between any of them and F. lucida.

Occurs mainly in the North Atlantic with few occurrences in the Arctic, Pacific and Southern oceans (in the latter as subsp. fissa). It ranges from marginal marine to deep sea (Fig. 46).

Occurs in the North Atlantic and Mediterranean (in the latter mainly as subsp. caribaea) primarily on the shelf with a single marginal marine record (Barbuda) and a few in the deep sea (Fig. 47).

Loeblich & Tappan (1987) place Stainforthia in the Superfamily Turrilinacea and Fursenkoina in the Superfamily Fursenkoinacea, whereas Haynes (1981) placed them both in the Buliminida. Stainforthia is initially triserial then biserial with an optically radial wall, while Fursenkoina is biserial with an optically granular wall. The majority of species in both genera were originally attributed to Virgulina. The species of Fursenkoina can be divided into those with elongate tests (bramletti, complanata, earlandi, punctata, sandiegoensis, schreibersiana, spinosa) and those with short tests (apertura, mexicana). Fursenkoina pontoni is intermediate.

This differs from other species in its very large aperture. The types are from the San Diego Trough in southern California, USA, and all other occurrences are from the Pacific Ocean (San Pedro Basin, California, USA, Japan and Sea of Okhotsk). This is a deep-water species with just a few occurrences shallower than 200 m (San Diego Trough, Uchio, 1960). In San Pedro Basin the species is most common at 2–3 cm sediment depth in the 63–150 μm fraction in April and October. It is deep infaunal (ALD 3.6 cm) in the Okhotsk Sea (Bubenshchikova et al., 2008).

The seasonal deposition of phytodetritus in Sagami Bay, Japan, is related to the spring bloom in phytoplankton (late February to May). In a time-series study in 1997–1998, S. apertura migrated into the phytodetritus layer in May and their protoplasm was green showing that they were feeding on fresh phytodetritus containing chlorophyll-a. There was a high concentration of juvenile individuals in the fluffy detritus layer and fewer in the sediment (Kitazato et al., 2000).

This is rare with only 30 occurrences all in California borderland basins, USA.

This has a very elongate test with 4–5 chambers in each row. There are scattered records from the Atlantic, Pacific and Southern oceans from marginal marine to deep sea. The greatest abundance is in the deep sea off Japan (Fig. 48).

It looks like a bolivinid rather than Fursenkoina. It occurs in the deep sea in the Gulf of Guinea, South Atlantic, Weddell Sea, Scotia Sea (where it reaches a maximum abundance of 67%) and Ross Sea.

It looks like a polymorphinid. There are few occurrences in the marginal marine (Indian River, USA, and NW African shelf), with most from the deep sea from North Africa to the South Atlantic and maximum off Japan.

This was described from the Miocene of Florida, USA. It is confined to the east and west coasts of the USA, the Caribbean and Baja California (Fig. 49). It is the most abundant species of Fursenkoina with nearly half the occurrences >10%. It occurs primarily in lagoon and shelf environments but it is also recorded from the continental slope in the Gulf of Mexico. Although most records are from sediment samples it is also found to be epiphytal in low abundance on various calcareous algae on Nevis (Wilson, 2007; Wilson & Ramsook, 2007).

The areas of high abundance are: San Francisco Bay, California, USA (Lesen, 2005), NW Gulf of Mexico (Phleger, 1951; 1956) and Puerto Rico (Seiglie, 1974). San Francisco Bay is an estuary with turbid water which is of normal salinity in the summer but diluted by runoff during the winter and spring (annual range of salinity 15–32). There are pronounced spring phytoplankton blooms. The standing crop of F. pontoni collected monthly over two years ranged from 0 to 304 per 10 cm³ sediment and was positively correlated with sediment TOC, nitrogen, amino acids and chlorophyll-a but not with sediment bacteria. Lesen (2005) suggests that measurement of as many potential food resources as possible is necessary to fully evaluate the food supply. The shelf and upper slope in the NW Gulf of Mexico have salinities of 35.5–36, temperatures of ~10–20°C but no records were made of potential food supply. Abundances reach >10% in 56% of the shelf samples and 44% of those from the slope (down to 227 m). The standing crop is 0–111 per 10 cm³.

The shelf off Puerto Rico has high abundances 0–91%, mean 41%. The standing crop ranges from 0–321 per 10 cm³. The inner shelf has salinities of 33.3–36.8, temperatures of 24–29°C and silty clay substrate. The area is subject to pollution from industry (fish-canning, animal feed, fertilizer factories) as well as from the human population. Near-bottom dissolved oxygen values range from 4.4–6.8 ppm. There had been a change in the microfauna prior to sampling and F. pontoni became the dominant species. As no other environmental factor had undergone any major change, the increase was attributed to pollution (although no measurements of pollutants were reported) so this cannot be confirmed.

In summary, F. pontoni is a warm-temperate stenohaline species able to tolerate low oxygen conditions and possibly elevated levels of organic pollutants. It is restricted to southern North America and the Caribbean.

Occurs in marginal marine environments in the Caribbean (where it reaches its highest abundance) and on the shelf in the Atlantic and Pacific oceans (Fig. 50).

It is found in marginal marine and borderland basins off California, USA, and in the deep sea off El Salvador.

This has a few occurrences in marginal marine environments and in the deep sea but is mainly a shelf form with maximum abundance in the Arctic. Most records are from the East Atlantic with a few from the Caribbean and Pacific USA (Fig. 51).

Most records are of Glandulina laevigata. This genus is restricted to the Arctic, Atlantic and Indian oceans with records from fjord, shelf and deep sea (Fig. 52). The highest abundance is in the slightly hypersaline Arabian Gulf shelf.

Although there are a few records from marginal marine environments this is essentially a shelf and deep-sea species occurring widely throughout the Atlantic, Pacific and Southern oceans (Fig. 53). It occurs where the mean sea floor organic C flux is ~15 g m² a^–1 (Altenbach et al., 1999). The range tolerated in the Gulf of Guinea is 0.8–80 g m² a^–1 (Altenbach et al., 2003). Schönfeld (2001) found it to be an oxic species based on measurements of pore water.

Many authors treat polymorphinids as a group. They occur in fjords, shelf and deep sea in the Arctic, Atlantic, Mediterranean and Pacific (Fig. 54). Although Globulina and Vasiglobulina span the same range of environments they are primarily shelf forms confined to the Arctic and Atlantic (Fig. 55). Originally the subspecies myristiformis was placed in Globulina gibba but subsequently it was not only raised to species status but transferred to Vasiglobulina. Most records of Globulina are of G. gibba and all are from fjord, shelf or deep sea in the eastern North Atlantic. Vasiglobulina myristiformis is likewise a shelf form known from the NE Atlantic and Mediterranean (Adriatic). Vasiglobulina sp. is recorded from the shelf of eastern USA (listed as a new but unnamed species by Poag et al., 1980). It is permanently anchored to large detrital grains and in this respect differs from Globulina. However, there is no evidence that V. myristiformis has an attached mode of life.

The species most widely distributed is Guttulina lactea which occurs in marginal marine, fjord and shelf environments in the North Atlantic with a single occurrence on the shelf off Japan. Guttulina problema, described from the Tertiary of Italy, occurs in shelf sediments in the Adriatic Sea and east USA. The other species, G. australis, G. austrica, G. communis, G. harrisi, G. quinqueloba, G. rectiornata and G. yamagazii have very restricted distributions. An unidentified species is very abundant in the Ob estuary, Russia, with a maximum abundance of 45.4% and a mean of 15.5% (5 samples). Considering all Guttulina species together, they occupy marginal marine (in the Arctic), fjord, shelf and deep-sea environments but mostly shelf seas (125 of 151 samples) in the Atlantic and Pacific oceans (Fig. 56).

There has long been confusion in the assignment of species between Gyroidina and Gyroidinopsis. Loeblich & Tappan (1987) consider that most species correctly belong in Gyroidinoides or Hansenisca. Fourteen species have stained (living) records and six of these are known only from the deep sea in the Pacific Ocean (broekhiana, gemma, multilocula, nitidula, quinqueloba and rotundimargo), Atlantic (perlucida) and Southern oceans (subplanata). Three species occur in shelf seas as well as the deep sea (neosoldani, orbicularis, umbonata). Gyroidina orbicularis occurs at variable sediment depths down to 8 cm in Sea of Okhotsk ALD₈ 1.9 cm (Bubenshchikova et al., 2008). It occurs where the mean sea floor organic C flux is ~3.5 g m² a^–1 (Altenbach et al., 1999). Taking all species together the distribution is shelf and deep sea in the East Atlantic and deep sea only in the West Atlantic, Pacific and Southern oceans (Fig. 57). In only one out of 573 occurrences is the abundance >10% and the mean percentages of all species ranges from 1.03 to 1.74% (Table 2). In the South Atlantic Gyroidinoides is associated with North Atlantic Deep Water (NADW) (Mackensen et al., 1995).

This has been recorded under various species names, including Protelphidium anglicum and Nonion tisburyensis. It is one of the characteristic shallow infaunal species of marginal marine environments (Murray, 2006). It occurs in 15% of the samples and has a mean abundance of 28% (Table 2) and maximum abundances of 100%. There have been several time-series studies of this form (Murray, 1968; Cearreta, 1988; 1989; Murray & Alve, 2000a) so it is known to be abundant throughout the year rather than just occurring at one season. It is strongly euryhaline, shallow infaunal, and feeds on diatoms and cyanobacteria (Murray, 2006). Molecular genetics shows it to be a single species (Langer, 2000). It is most commonly present in intertidal to shallow subtidal brackish marginal marine environments but it is also present on marshes and there are a few occurrences in fjord and shelf environments (Fig. 58 lower). The North Atlantic and Gulf of Mexico are the main areas of occurrence. In the NE Atlantic the northern limit appears to be southern Scandinavia (Oslofjord, Norway). Its absence from the Baltic cannot be due to a salinity control as the species is euryhaline. Perhaps the water temperature never reaches a level suitable for reproduction. In the Adriatic it avoids substrates with seagrass and higher amounts of blue-green algae and shows a good correlation with the diatom Nitzschia as a food source (Hohenegger et al., 1989). In the NW Atlantic its northern limits vary: it does not occur in marshes north of Georgia or in marginal marine environments north of Cape Cod. The only record in the Pacific Ocean is from marsh in New Zealand.

Under experimental conditions sediment collected from 140 and 195 m from Oslofjord was kept in small sealed jars (to simulate shallow-water conditions) for 34 weeks at the end of which small Haynesina germanica were present in some of the containers although they were not present in the samples when collected (Alve & Goldstein, 2003). Under experimental conditions with varying temperature (12 and 22°C) and salinity (12, 22, 36) it grew abundantly at all salinities and the highest numbers were reached at 12°C (Goldstein & Alve, 2011). When buried in sediment under experimental conditions it did not climb up to the sediment surface (Lee et al., 1969).

This is perhaps the cooler-water equivalent of H. germanica although it may require warm summer temperatures for reproduction (Scott et al., 1977). It occurs predominantly in marginal marine environments (maximum abundance in Canada) and to a lesser extent in marshes and fjords. It features in the Arctic Ocean and the most southerly occurrence in the NW Atlantic is in Long Island Sound, USA (Fig. 59). The record in Arcachon lagoon, Biscay, is almost certainly a misidentification. In an experiment it was found to be a highly mobile species (Schafer & Young, 1977).

Apart from occurrences in the Mediterranean this species is absent from the East Atlantic. It occurs on marshes/mangals and in marginal marine environments in the Atlantic seaboard of North America and Caribbean and in the Pacific (Fig. 60). It is found down to 45–50 cm sediment depth in an Australian mangal (Berkeley et al., 2008).

This epifaunal aragonitic species from the Atlantic, Pacific and Indian oceans typically occurs on the continental slope but is also known from shelf seas (Fig. 61). High abundance is known from Biscay and the South Atlantic, although the mean abundance is modest. It occurs where the mean sea floor organic C flux is 10–15 g m² a^–1 (Altenbach et al., 1999). In Biscay it occurs in eutrophic to oligotrophic conditions and is shallow infaunal (Fontanier et al., 2002; 2006; Mojtahid et al., 2010). The range tolerated in the Gulf of Guinea is 0.8–62.3 g  m² a^–1 (Altenbach et al., 2003). Schönfeld (2001) found it to be an oxic species based on measurements of pore water. In the South Atlantic it is associated with NADW (Mackensen et al., 1995).

The occurrences in the Atlantic, Mediterranean, Pacific and Indian oceans are confined to marginal marine and shelf environments (47 and 53% respectively, Table 2) mainly in temperate settings (Fig. 62). The highest abundance is in marginal marine Tomales Bay, California, USA, in muddy sediments and it is especially abundant in winter (maximum 56%; 28 out of 38 samples >10%). The annual salinity range is 20.3–33.5 and temperature 7–12°C so the species was regarded by the authors as estuarine but it is also correlated with fine-grained sediment (McCormick et al., 1994). On the Adriatic shelf a single station at 32 m was sampled several times throughout the year. This species occurs predominantly in the top centimetre of the muddy sediment but at different times of the year it also extends down to the maximum depth sampled (7 cm) so has been described as ‘potential infauna’ (Barmawidjaja et al., 1992).

The types are from the Baltic where it was recorded adherent on seaweed. Although there are rare occurrences in the Pacific and Indian oceans, this is essentially a NE Atlantic and Mediterranean species occurring in fjord, shelf and deep sea (Fig. 63). It has peak abundance in the top cm of sediment in Biscay (Hess & Jorissen, 2009).

Morphospecies of the unilocular genus Lagena can be differentiated only on a few criteria, namely the shape of the chamber, the presence or absence of any wall surface texture (‘ornament’) and the nature of the aperture. Notwithstanding this basically simple morphology, numerous genera have been erected primarily on the shape of the chamber. Here species that have been selected as types of other genera are also considered under Lagena as there seems no benefit in increasing taxonomic confusion by adding these new genera: acuticosta, type of Obliquina Seguenza, 1862; gracilis, type of Procerolagena Puri, 1954; hispidula, type of Pygmaeoseistron Patterson & Richardson, 1987. It has been claimed that Lagena is parasitic on other foraminifera (Haynes, 1981, p. 54) but no evidence in support of this has been published. MacGillivray observed L. laevis adherent on seaweeds and on the byssus of a modiolid bivalve (cited in Williamson, 1848).

Although more than 30 species of Lagena are recorded in living (stained) assemblages in 10.3% of the dataset, in only 4 samples out of a total of 825 do they have an abundance >10% and their mean abundance is merely 0.82% so they are undoubtedly rare. Collectively they are distributed in marginal marine to deep sea of all the oceans with just a single record from a mangal. However, individual species show restricted distributions. The highest abundance of Lagena is an unidentified species in an Indonesian mangal (14%). The other high abundances are all 10% and from off Japan: L. apiopleura and L. sulcata spicata at 150 m and L. striata at 300 m.

This occurs primarily on shelf seas in the North Atlantic and Adriatic (mean 0.66%) with a few occurrences in marginal marine and deep-sea settings in the North Atlantic (Fig. 64).

With a mean abundance of 0.70% it has a similar geographical distribution to L. clavata but also with occurrences in Arctic Ocean fjords and shelf. In the North Atlantic it occurs primarily in shelf and deep-sea settings.

With a mean abundance of 0.74% it occurs mainly in shelf seas in the North Atlantic but with a single occurrence in the South Atlantic (Fig. 65). It is also present in the Arctic Ocean down to 374 m and in a marginal marine lagoon in the Caribbean.

With a mean abundance of 0.69% it is most commonly present on the Adriatic Shelf but is also sporadically present in the North and South Atlantic as well as the Pacific (Fig. 66). Its maximum abundance is in the deep sea off Japan (300 m) and it occurs down to 494 m in the Gulf of Cadiz and 3891 m in the Gulf of Guinea.

With a mean abundance of 0.73% it is sporadically present from marginal marine to deep sea in the North Atlantic and shelf in the Mediterranean (Fig. 67). In the Norwegian Sea it extends down to 693 m.

This species is generally rare (mean 1.42%) and the maximum abundance is 7% on the shelf off northern Spain (Diz et al., 2004). In this area it is also recorded down to a depth of 9 cm in the sediment. It occurs sporadically in estuaries in southern England, a Thalassia habitat in Jamaica, and a fjord (Loch Etive, Scotland) but is generally found in shelf environments off NW Europe and eastern USA (Fig. 68). Of the 61 occurrences only 3 are from the USA and Jamaica with a maximum abundance of 0.30% and a mean of 0.26%.

There are surprisingly few records of this species (35) and all are from the deep sea in the Atlantic Ocean, South China and Weddell seas (Fig. 69). Notwithstanding this rarity, 22 live individuals collected from 775 m off New England, USA, were used in experiments. They were placed on the sediment surface (using sediment from the sampling location) and photographed at regular intervals over a period of days. They moved over and in the sediment and climbed the walls of the containers. Surface tracks were made by individuals moving in a flat position and also by others moving with the test held vertically. Subsurface movement led to cracks in the sediment surface. Feeding traces were arc-shaped and made by the pseudopodia moving over the sediment surface. Average daily movements were 16.43 and 11.54 mm individual^–1 for two consecutive months (Weinberg, 1991). The only record of the genus occurring in shelf seas is that of Laticarinina sp. living down to 9 cm (limit of sampling) in coarse sediments subject to disturbance off northern Spain (Diz et al., 2004).

Many records are left in open nomenclature but 18 species are also recorded and one of these (peregrina) is sometimes assigned to Neolenticulina. This is primarily a deep-sea species but it also occurs in small numbers on the shelf. With the exception of rare occurrences in the South China Sea this species is confined to the eastern Atlantic. It is tolerant of dysoxic and suboxic pore water but its maximum abundance is in high oxic waters close to the sediment surface, therefore, it is not a reliable indicator of low oxygen conditions (Schönfeld, 2001). With a mean abundance of 0.39% it occurs very infrequently in marginal marine and fjord and mainly in shelf and deep-sea environments, in the Arctic, Atlantic, Mediterranean, Pacific, Indian and Southern oceans (Fig. 70). The only abundance >10% is from the shelf off Japan. Lenticulina gibba (mean 0.48%, maximum 1.72%) is found in shelf and deep sea in the North Atlantic, Mediterranean and South China Sea.

These genera have been recorded in only 26 samples with an overall mean of 0.41%. Each species is very restricted: bachei (1 record), bradyi (2), glabra (15), obesa (8). All records are from the North Atlantic, Mediterranean and South China Sea shelf and deep sea (maximum 1.32% off Greenland) (Fig. 71). Marginulina glabra occurs where the mean sea floor organic C flux is ~20 g m² a^–1 (Altenbach et al., 1999).

Basically there are two morphotypes of Melonis: compressed or inflated. The compressed forms are generally identified as M. barleeanum but sometimes as M. affinis, M. parkerae or M. zandamae. Some authors have found it impossible to separate barleeanum and zandamae (Schmiedl et al., 1997). The inflated forms are M. pompilioides otherwise sometimes called M. sphaeroides

This is occasionally present in fjords but it is primarily a shelf and deep-sea form occurring widely in the Arctic, Atlantic, Pacific and Southern oceans (Fig. 72). In the Arctic Ocean it occurs in seasonally ice-free areas (Wollenburg & Mackensen, 1998). The mean values are 6.4% fjord, 7.5% shelf and 8% deep sea and maximum values reach 86% off Portugal. It is the dominant species in the top 2 cm of sediment on the continental slope and in canyons off Portugal (Nardelli et al., 2010). In the South Atlantic it is present beneath surface waters showing seasonally varying productivity (Mackensen et al., 1995). It occurs where the mean sea floor organic C flux is 8 g m² a^–1 although it tolerates a much greater range (Altenbach et al., 1999). Off NE Greenland the peak abundance is at 1–3 cm down core (Ahrens et al., 1997) but in Biscay it is deep infaunal (Fontanier et al., 2003). It shows vertical migration according to changing environmental conditions and availability of food (Linke & Lutze, 1993). Off Iberia there is tolerance of dysoxic and suboxic pore water but its maximum abundance is in high oxic waters close to the sediment surface so it is not a reliable indicator of low oxygen conditions (Schönfeld, 2001). But elsewhere, it seems to favour dysoxic sediments linked to a redox front (Licari et al., 2003; Fontanier et al., 2005). It seems to be adapted to live in organic-rich sediments in submarine canyons (Schmiedl et al., 2000). In Biscay it occurs in eutrophic to mesotrophic conditions (Mojtahid et al., 2010). There appears to be a 2–3 month delay between the maximum arrival of food and reproduction because bioturbation is superficial and slows the rate of food transfer into the sediment (Fontanier et al., 2003). In a two-year experiment, where the fauna was deprived of fresh phytodetritus, it increased in abundance indicating that it feeds on degraded food (Alve, 2010) but others have considered that it is independent of the vertical flux of food (Fontanier et al., 2005).

This is generally less abundant than M. barleeanum (Table 2). There are a few somewhat doubtful records from lagoons in the Caribbean but most occurrences are on the shelf and deep sea in the Atlantic Ocean (Fig. 73). In Biscay it occurs in oligotrophic conditions (Mojtahid et al., 2010). In the South Atlantic it is present beneath surface waters showing seasonally varying productivity (Mackensen et al., 1995).

With the exception of two records from marginal marine and fjord environments, this genus is otherwise confined to shelf and deep sea (Fig. 74). The mean abundance is 0.60% and the maximum 2.0%. Half the records are as sp. (26 out of 52) and individual species have few occurrences: albatrossi (1), calomorpha (12), catesbyi (2), perversa (7), subsoluta (2).

With the exception of occurrences in an Australian mangal (as Haynesina which may be a misidentification for H. germanica), this form is confined to the Atlantic Ocean on marsh (rare), marginal marine, fjord and shelf (Fig. 75). In Christchurch Harbour, England, the optimum temperature appeared to be 5–10°C (Murray, 1968). This species is abundant in the intertidal zone of the Exe estuary, England, because the salinities are only slightly brackish (Murray, 1980; 1983) and it reproduces every 3–4 months throughout the year. The range of salinity tolerated in marginal marine southern Scandinavia is 24–28 (Alve & Murray, 1999) but the upper limit is higher (35), as seen from the shelf occurrences. In the Adriatic it shows a high correlation with the density of seagrass and to food resources of blue-green algae and diatoms (Hohenegger et al., 1989).

More than half the occurrences are in fjords and the rest evenly divided between shelf and deep sea. This is a cold-water species confined to the Arctic, and high-latitude North Atlantic and Pacific oceans (Fig. 76). In the Arctic Ocean it occurs in seasonally ice-free areas (Wollenburg & Mackensen, 1998). Korsun & Hald (1998; 2000) found it to be associated with nutrient-rich glacially-distal areas of fjords where it reproduces in spring in response to the phytoplankton diatom bloom. The maximum abundance of 87.7% is on the Grand Banks, Canada. The only record from the Pacific seaboard of North America is from cold methane seeps at 500–525 m off northern California, USA, where it occurs in very low numbers down to 3 cm in the sediment (Rathburn et al., 2000). This is similar to the subsurface depths in the Sea of Okhotsk (Bubenshchikova et al., 2008) and off NE Greenland (Ahrens et al., 1997) although it extends down to 10 cm in the Barents Sea (Ivanova et al., 2008). It migrated vertically by ~1 cm in response to experimentally altered oxygen conditions (Alve & Bernhard, 1995).

A deep-sea species found only in the East Atlantic in Biscay, Gulf of Guinea and the South Atlantic, although the types were from off Tasmania, Australia.

Like N. pusillus this is confined to the deep sea in Biscay, Portugal, Gulf of Guinea to the Scotia Sea and Weddell Sea with rare occurrences in the West Mediterranean and off the USA (Fig. 77). In Biscay it occurs in oligotrophic conditions (Mojtahid et al., 2010) in the surface layers of sediment (Fontanier et al., 2002).

Although numerous species are recorded they are all rare. There are isolated occurrences in marsh, marginal marine, and fjord but most are from the shelf and deep sea (Fig. 78). The mean is low (0.86%) and the maxima 5.88% and 5.62% from the shelf and deep sea, respectively.

Of the three species discussed two (O. sidebottomi Scotia and Weddell seas and O. tener Scotia Sea) are confined to the deep sea, while O. umbonatus also rarely extends on to the shelf (Fig. 79). The mean for O. umbonatus is low (3.39%) but high abundances (56%) are attained to the north and west of Norway. It occurs where the mean sea floor organic C flux is 2 g m² a^–1 while that for tener is 3 g m² a^–1 (Altenbach et al., 1999). The molecular genetics of bipolar examples of O. umbonatus show high similarity (Pawlowski et al., 2007).

This deep-sea form is known only from the Gulf of Guinea and SE Atlantic and from the South China Sea.

This is a very distinctive species with little possibility of it being misidentified, as pointed out by Williamson when he named it in 1858. Although Williamson gave no reason for choosing the generic name Patellina it must surely be based on the morphological similarity with the limpet (Patella). With its planoconvex form it has the morphology of an attached or clinging species and this has been confirmed by observation. Myers (1935a, b) studied material from tide pools of California, USA, and noted that the tests are attached to various firm substrates ‘that support a sparse population of diatoms and other unicellular organisms which may serve as food’. However, the tests were not permanently anchored because when he washed coralline algae from the pool, individuals of P. corrugata crawled up the sides of the dish. Unfortunately Myers gave no information about the abundance of the species in the tide pools beyond stating that they were the source of ‘the most plentiful supplies’. However, Cooper (1961) recorded abundances of <3% of this species in his study of Californian tide pools.

The life cycle was worked out by Myers (1935a) and Berthold (1976) and the cultures used by the latter were ‘derived from a single agamont’. Myers was the first to demonstrate the whole dimorphic life cycle in a foraminiferan. Under experimental conditions maximum gamontogamous (requiring two or more individuals to come together) reproduction occurred at 21°C with an (obligatory) alternation of generations occurring on average every 41 days (Myers, 1935b; Goldstein, 1999).