Shell slender, ovate, with two deep strictures. Length of the three joints = 1:4:4, breadth= 2:5:5. Cephalis hemispherical, with a large pyramidal horn longer than the half shell. Thorax conical, spiny, prolonged above the lumbar girdle into three slender, triangular, prismatic wings, which are about as long as the shell, and slightly curved downwards, with lower convexity. Abdomen inflated, with wide, truncate mouth, pores irregular, roundish, of very different sizes.
Dimensions:
Length of the three joints, a 0.03, b 0.08, c 0.08; breadth, a 0.04, b 0.1, c 0.1. |