218 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
rest of the base. Aperture forming a broad semioval, of which the colu- 
mellar side forms the short diameter; outer lip thin and semitransparent; 
columella slender and curved; parietal wall covered by a thin callus. 
Greater diameter, 1.6; lesser diameter, 1.2; altitude, 1.2 mm. (Bartsch.) 
Type in United States National Museum, No. 109470. Type locality, 
Unalaska, Alaska. 
Range. Known only from type locality. 
Subgenus Docomphala Bartsch, 1907 
Vitrinella stearnsii Bartsch, 1907 
Plate 106, figs. 11, 13, 14 
Proceedings of the United States National Museum, 32:169; fig. 4. 
Shell depressed, lenticular, a little more convex above than below. 
The nepionic portion of the shell consists of the first one and a half turns, 
which are small, slightly convex, and smooth. The turns which succeed 
the nepionic part of the shell are strongly, obliquely, transversely ribbed on 
the upper side, but these ribs gradually grow weaker as the shell increases 
in size and disappear entirely after one and one-half turns, the remaining 
portion being marked by mere lines of growth on the upper surface. Pe¬ 
riphery of the last whorl well-rounded. Base very gently rounded, crossed 
by rather strong incremental lines. Umbilicus wide and open to the very 
apex, decidedly angulated at the outer margin. The columellar wall is 
strongly concaved from the outer angulation to the junction with the 
preceding whorl, the inner half of it bears a series of strong ribs behind 
the aperture. Aperture decidedly oblique; outer lip acute, forming a regu¬ 
lar semioval of which the parietal wall and columella form the short diam¬ 
eter; columella short, stout, concave; parietal wall covered by a thick 
callus, which renders the peristome continuous and forms an acute angle 
with the outer lip posteriorly. The parietal callus and columella form a 
strongly sigmoid curve. Greater diameter, 3.8; lesser diameter, 3; altitude, 
1.5 mm. (Bartsch.) 
Type in United States National Museum, No. 74011. Type locality, 
Monterey, California. 
Range. Known only from type locality. 
Vitrinella berryi Bartsch, 1907 
Plate 107, figs. 4, 5, 6 
Proceedings of the United States National Museum, 32:170; fig. 5. 
Shell small, semitransparent, lenticular, with the upper part only 
slightly more convex than the base. Nepionic whorls forming a little more 
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