Assiminea crassitesta
Assiminea crassitesta is a species of small operculate snail, a marine gastropod mollusc or micromollusc in the family Assimineidae.
Description
The length of the shell varies between 3½ mm and 4 mm., its maximum diameter between 2½ mm and 2¾ mm.The shell is either rimose or perforate. The perforation is circumscribed by a more or less distinct keel. The shell is ovate-conical, solid, uniformly yellowish-horn-colored or tawny-horn-colored, and shining with an oily luster. The spire is conical with sides that are slightly convex. The apex is rather acute.The shell contains 6½ rather convex whorls, separated by a distinctly impressed suture. They are obliquely striate and very faintly spirally lineolate. The whorls are encircled below the suture by a single, slender keel. The body whorl is slightly swollen, initially lightly angulate at the base, then rounded, and very slightly constricted before the aperture. It is equal to 2/5 to 3/7 of the height of the shell. The aperture is small, very oblique, ovate, and more acuminate above than below. The peristome is simple and acute angularly. The right margin is slightly sloping downward from the suture, and sub-retracted in its middle part.