Revision of the Foraminiferal Family Pseudoparrellidae Voloshinova

Abstract

The Pseudoparrellidae Voloshinova, 1952, is recognized as a disyinct family of the Discorbacea (Foraminiferida) on the basis of trochospiral tests, hyaline calcite walls with radial crystalline structure monolamellid septa and a vertical aperture parallel to the periphery of the test.  As redefined, the family contains six genera:  Pseudoparralla Cushman and ten Dam, Epistominella Husezima and Maruhasi, Megastomella Faulkner de Klasz and Rerat, Stetsonia F.L. Parker, Concavella Lipps, gen. nov. (type species Pulvinulinella gyroidinaformis Cushman and Goudkoff), and Ambitropus Lipps, gen. nov. (type of species Epistominella evax Bandy). Species of the Pseudoparrellidae occur in Oligocen to recent deposits throughout the world.  Nineteen species and two varieties of foraminifera have been recorded from California as Pseudoparrellidae.  A new genus, Eilohedra (type species Epistominella levicula Resig), is erected in the Eponididae to contain species superficially similar to pseudoparrellids but differing in the bilamellid wall structure.