Darvasitinae Leven 1992

Subfamily DARVASITINAE Leven, 1992 Test small to medium in size, from oval to subcylindrical, less often pseudofusiform, usually with smoothly rounded ends. The shape of the test is established in the early whorls and remains almost unchanged; the test only slightly lengthens as it grows. The spiral is wound closely and evenly with a very smooth and slow increase in the height of volutions. The initial chamber is small and medium in size. The wall has a distinct keriotheca, moderate, gradually increasing thickness. The septa are folded along their entire length. The folding covers only their lower edge, so the arches are usually flat and low. Cuniculi are observed in the outer whorls. The aperture occupies a stable position gradually and rapidly expanding. The septa along the edges of the aperture are thickened by secondary deposits, which can also accumulate in the axial part of the test. Composition: Darvasites A. D. Miklukho-Maklay, 1959; Darvasites (Alpites) Davydov, Krainer & Chernykh, 2013; Nagatoella Thompson, 1936; Tieliekella Da in Da & Sun, 1983.