Brief SummaryRead full entry
Protatlanta souleyeti is a small species (<2 mm shell diameter) that is distinguished from all other atlantids by its calcareous shell and glass-like, cartilaginous keel, composed of conchiolin. The truncated keel extends from the shell aperture to about one-half of the shell's circumference in adult animals. The shell spire consists of three whorls and is slightly elevated and rounded, with incised sutures. In all P. souleyeti from the world oceans the shell spire lacks surface sculpture, although in the Atlantic Ocean there is a second form that has a low spiral ridge centered on the second whorl and extends to the third whorl, and a lower and shorter secondary spiral ridge inside the first one. The eyes lack a transverse slit in the distal pigmented tissue (type a, Richter, 1961), and the operculm has a large apical gyre (macro-oligogyre; type a, Richter, 1961). Geograpic distribution is cosmopolitan at tropical to subtropical latitudes.