Cerion sarcostomum Pilsbry and Vanatta, 1896

Original Description

"Cerion sarcostomum Pil.bry & Vanatta. Pl. XI, fig. 16.

Shell solid and strong, subcylindrical, but slightly wider below; whitish. Whorls 11 to 11½, slightly convex, the earlier 6 forming a convexly tapering cone with extremely obtuse apex, almost dome­shaped at top; passing gradually into the cylindrical portion of shell, which consists of 5 to 6 whorls. Sculpture, somewhat irreg­ular and unequal, straight ribs, about as wide as the intervals, about 25-30 on last whorl. These ribs are strongly developed on the cylindrical portion of the shell, but the cone is very densely, finely and sharply striated, the earliest whorl only being smooth.

Aperture small, less than one-third the total length of shell, pinkish-flesh colored in the throat; peristome well reflexed, recurved, more or less thickened on the inner edge of the face; parietal callus thick and heavy, its edge elevated. Parietal tooth rather strong and moderately long; axial fold moderately conspicuous.

Alt. 34, diam. l1½; alt. of aperture 10 mm. Little Inagua, Bahamas.

Some specimens are larger than the above dimensions; one worn and broken" crab-shell" before us would probably be not less than 40 mm. alt. if perfect. It is not unlikely that forms occur with the ribs obsolete, as in the allied C. columna.

C. sarcostomum clearly belongs to the immediate group of C. creta­ceum and C. columna. The latter has a very dark aperture, broadly flanged lip and less obtuse apex. C. cretaceum lacks sculpture except on the basal whorl, is absolutely cylindrical, with light mouth and excessively short terminal cone, while the present species is more tapering, with the cone decidedly longer, gradually passing into the cylindrical portion.

This species is, we believe, the first one to be reported from Little Inagua. It is extremely likely that C. cretaceum, described without locality, will prove to inhabit some part of the Inagua group, when it is re-discovered." (Pilsbry & Vanatta, 1896:331-332)

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