Page:American Seashells (1954).djvu/309

Rh 3 to 4 inches in length, characteristically sinistral (left-handed), 4 whorls, with the smoothish nucleus indented. Sculpture of 6 to 12 very oblique, low, rounded axial ribs and numerous (often paired) raised spiral threads. Color ash-gray with a light brownish yellow periostracum. Interior of aperture tinted with tan. Operculum much smaller than the aperture. Dextral (right-handed) specimens are rarities. Fairly common in deep water. Genus ]umala Friele 1882 (Bermgius Dall) Jumala crehricostata Dall Thick-ribbed Buccinum Figure 51b Alaska. 4 to 5 inches in length, moderately heavy, with 5 to 6 whorls. Charac- terized by the very strong, rounded spiral cords (3 to 4 between sutures) which on the base of the shell tend to be flat-topped. Periostracum grayish brown, thin and semi-glossy. A very handsome, but not commonly acquired species which occurs from 80 to 100 fathoms. Jumala keitnicotti Dall Kennicott's Buccinum Figure 5ig Alaska. 5 to 6 inches in length, not very heavy. Characterized by about 9 strong, arched, somewhat rounded axial ribs extending from suture to suture, and, on the body whorl, extending % the way down the whorl. Spiral sculpture of microscopic scratches, except on the base where there are a dozen or so weak threads. Periostracum light-brown, thin, and usually flakes off in dried specimens. Shell chalky and whitish gray in color. Not uncommon in sev- eral fathoms of water; rarely in very shallow water. Genus Coins Roding 1798 Cohis stimpsoni Morch Stimpson's Colus Plate 23X Labrador to off North Carolina. 3 to 5 inches in length, fusiform, moderately strong, chalk-white in color, but covered with a semi-glossy, light- to dark-brown, moderately thin periostracum. Length of aperture about half the length of the entire shell. Sculpture of numerous incised spiral lines. Fairly common from i to 471 fathoms.