CLASS GASTROPODA 
211 
but usually covering the whole surface; in five young specimens the sur¬ 
face over the sculpture is somewhat polished; in adults it has a more rude 
appearance; aperture oval, wide; the outer lip flexuous as in Buccinum, 
more or less (in some specimens, very much) reflected; margin simple, 
smooth; body polished, the surface slightly excavated and glazed; pillar 
thin, simple, twisted; the axis widely pervious in the young, minutely or 
not at all in the adult; canal short, wide, slightly recurved; there is no 
siphonal fasciole; operculum large, thin ovoid, slightly curved, with an 
apical nucleus. Max. long, of shell, 32; of altitude, 18 mm. (Dali.) 
Type in United States National Museum. Type locality, United States 
Fish Commission Station 2839, near the islands off Santa Barbara, Cali¬ 
fornia, in 414 fathoms. 
Range. Bering Sea, in 27 fathoms, to San Diego, California, in 636 
fathoms. 
SECTION HELICOFUSUS Dali, 1916 
Plicifusus laticordatus Dali, 1907 
Plate 13, fig. 4 
Miscellaneous Collections, Smithsonian Institution, 50:161. 
Shell a deeply orange-tinted, with four whorls, strongly recurved, 
short canal, but with the spirals about twice as wide as in the type, flat 
above and with distinctly channeled interspaces in which the incremental 
lines are strong. Long, of shell, 20; max. lat., 11; and of the last whorl, 
15; aperture, 11 mm. (Dali.) 
Type in United States National Museum, No. 122664. Type locality, 
Station 3279, in 41 fathoms, Bristol Bay, Alaska. 
Range. Bering Sea to Straits of Juan de Fuca. 
Genus COLUS Bolten, 1798 
Shell long-fusiform, slender, with numerous moderately rounded 
whorls, the nucleus chrysodomoid, the shell structure usually white, often 
with a chalky external layer under a conspicuous, usually brownish, ad¬ 
herent periostracum; sculpture spiral, seldom very strong, sometimes 
nearly obsolete, never axially plicate or ribbed; aperture of moderate 
size, the outer lip simple, acute, not thickened or reflected, rarely slightly 
expanded; pillar smooth, the inside of the outer lip not lirate or denticulate; 
canal varying in length, usually somewhat tortuous or, when short, re¬ 
curved ; operculum filling the aperture, formed as in Chrysodomus. (Dali.) 
Type. Murex islandicus Gmelin. 
Range. Arctic to San Diego, California; circumboreal. 
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