The beyrichiacean ostracode genus drepanellina

Drepanellina clarki Ulrich & Bassler 1923, type species of Drepanellina Ulrich & Bassler 1923, has been studied with particular regard to the ventral morphology of the crumina. The genus shows the incision through the margin of each valve characteristic of the subfamily Zygobolbinae. This incision is connected with a plica in the striate field of the crumina which does not occur in the zygobolbine genera Zygobolba, Noviportia, and Slependia.