Page:American Seashells (1954).djvu/321

Rh Subgenus Hinia Gray 1847 Nassarms ambiguus Pulteney 1799 Variable Nassa Plate 231; figure 53a North Carolina to Florida and the West Indies. V2 inch in length, relatively light-shelled, usually pure white in color, but occasionally with i or 2 narrow, spiral bands of light yellowish brown. Number of strong, axial ribs per whorl varies from 8 to 12. Upper part of whorl sometimes shouldered. Numerous spiral, rounded cords are strong or weak. Parietal shield enamel-v/hite, usually not well-developed. N. con- sensus Ravenel is possibly only a form of this unusually variable species (fig. 53b). Nassarius trivittatus Say New England Nassa Plate 23 j Nova Scotia to South Carolina. % inch in length, rather light-shelled, 8 to 9 whorls; nuclear whorls smooth. Whorls in spire with 4 to 5 rows of strong, distinct beads. Parietal wall thinly glazed with white enamel. Outer lip sharp and thin. Whorls slightly channeled just below the suture. Color light-ash to yellowish gray. Common from shallow water to 45 fathoms. Nassarius perpinguis Hinds Western Fat Nassa Figure 530 Puget Sound to Lower California. % to I inch in length, fairly thin, with a rather fragile outer lip. Similar to N. calif ornianus, but with much finer sculpture (usually finely cancellate or minutely beaded), and yellowish white in color with 2 or 3 narrow, spiral bands of orange-brown, one of which borders the suture. The sculpture is variable with spiral threads often predominant. Very abundant along most of the coast. Intertidal flats to 50 fathoms. Nassarius calijornianus Conrad Californian Nassa Squaw Creek, Oregon, to Lower California. I inch in length, without a thick parietal shield and the outer lip not thickened. Shell with numerous, rather coarse beads arranged in 20 to 30 axial, slanting ribs. 11 to 12 spiral threads on the last whorl; 5 to 7 on the whorls above. Color white with an ashy or yellow-gray periostracum. Moderately common just offshore to 35 fathoms. Compare with perpinguis.