Macrarene californica

(Original description by W.H. Dall) The height of the shell attains 15 mm, its diameter 23 mm. The rude, yellowish-white shell is large for the genus. It has a depressed shape with about six whorls, carrying at the shoulder six blunt, large, projecting tubercles. The nucleus is small, the nepionic whorls reticulate and flattened. The later whorls are keeled bluntly at the shoulder, behind which they are flattened. On the flat area are two strong, elevated, spiral threads (which later disappear) close together, with the channels on either side reticulated by subequal and subequally spaced radial threads. On the body whorl all the sculpture on the upper part of the whorl, except the keel connecting the tubercles at the shoulder, has disappeared. The surface of the shell is of a spongy nature and all the sculpture is obscure as if deliquescent. The base of the shell is rounded with a large spiral, deep umbilicus, having one entering a spiral keel which ends at a projection of the pillar lip. The verge of the umbilicus is rounded and spongy. Outside of this ridge in the young it is constricted by a row of pits between which and the periphery are some obscure spirals in some specimens. The aperture is circular within, and when fresh, brilliantly pearly, but the pearly coating is very thin and seems to disappear in dead shells. The outer margin of the aperture, which is very thick, is modified by the umbilical keel and other sculpture. The operculum is multispiral, with the external edges of the whorls fringed, very concave, and showing hardly any calcareous deposit.

This species is usually covered with Polyzoa, Lithothamnion, and other adherent matter, which obscures its appearance, but the shell itself is so rude, spongy, and bleached in appearance that the actual surface is often discriminated only when examined with a lens.[3]

This marine species occurs in the Gulf of California, Western Mexico

• To Biodiversity Heritage Library (1 publication)
• To World Register of Marine Species