½ to ¾ inch in length, dull whitish, 7 to 8 whorls, moderately slender. Characterized by the smoothish sides of the whorls and by the spiral ramp below the suture which bears 12 to 14 short, horizontal ribs per whorl. Early whorls may have weak axial ribs running from suture to suture. Spinal sculpture of microscopic, numerous scratches. O. crenimarginata Dall is this species. Very common among rocks at low tide.
Genus Amaea H. and A. Adams 1854
Texas coast to Yucatan.
1½ to 2½ Inches in length, thin but strong; without an umbilicus. With about 15 rather strongly convex, pale-ivory whorls which have a dark brownish band at the periphery and a solid brown area below the basal ridge. About 22 low, irregular costae per whorl. Numerous spiral threads are fine, and produce a weak, reticulated pattern. Not very common, but occasionally washed up on Texas beaches.
Subgenus Scalina Conrad 1865
(Ferminoscala Dall 1908)
North Carolina to both sides of Florida to Barbados.
1 inch in length, elongate, thin but strong; with about 16 whorls which are beautifully reticulated by strong, sharp threads. Color straw to pale-brown with 2 light and narrow brownish bands, one above and one below the periphery. Commonly dredged off Florida from 13 to 120 fathoms.
Genus Epitonium Röding 1798 (Scala)
Subgenus Epitonium s. str.
South half of Florida to the Lesser Antilles.
½ to ¾ inch in length, stout. With umbilicus fairly narrow to wide, and very deep. 7 to 8 whorls attached by the costae (10 to 12 per whorl). China-white, rarely with a trace of brown to pinkish brown undertones. Moderately common from a few feet to 160 fathoms. E. swifti Mörch and E. contorquata Dall are this species.
Do not confuse with E. occidentale Nyst (Western Atlantic Wentletrap) from the same areas. It is not so stout, has 12 to 15 costae per whorl, a very
