Borgert
Diagnosis: Shell compressed lenticular, elliptical, ovate, or nearly circular in side view, or nearly triangular with convex sides. Mouth with a straight or slightly curved process obliquely tilted over the opening, third to half the shell diameter, terminating in three teeth, one simple dorsal and two parallel and tilted obliquely over the mouth. Middle tooth sometimes larger and stouter than the two paired ones, sometimes only in form of small protuberance, sometimes lacking altogether, with all intermediate transitions.
Length: 0.155-0.175 mm.