Notes on the benthic foraminiferal genus Heteromorphina R.W. Jones, and Heteromorphina amplivestibulata sp. nov

Abstract. Oolina heteromorpha Parr, 1950, the type species of the genus Heteromorphina R.W. Jones, 1984 is demonstrated to be a junior synonym of Lagena collaris Cushman, 1913. In addition, two of the three species transferred by Jones to this genus are shown to belong to other genera. From the Miocene of DSDP Site 357 (Leg 39), located on the Rio Grande Rise, a new species, Heteromorphina amplivestibulata, is described and illustrated. It is characterized by an extremely large chamberlet in comparison to the principal chamber, which has a slightly produced caudal structure with a hollow central canal.