The material for the present article was a collection of bivalves collected by V. D. Voznesensky in 1957. D. Voznesensky in 1956 from the Middle Devonian deposits of the Karaganda region of Central Kazakhstan. The merit of the collection is a large number of specimens and their good preservation.

Diagnosis. “Shell oval in shape, smooth or with concentric jets, with prosogyric apices shifted forward. Along the locking margin the teeth are continuous; in the posterior branch up to 50; in the anterior branch 7-15 larger teeth”...