134 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
arcuatum. Long., 35; lat., 34; altit. anfr. ult., 31; platit. apert., 20; col. 
ext. long., 17 mm. (Middendorff.) 
Shell fissured, quite thin, pellucid, ovate-globose; with four whorls, 
the last inflated, appressed at the suture; with short obtuse spire; with 
aperture broad, longitudinally ovate, emarginate behind on the next to the 
last whorl; with very thin columella lamina, covering the entire umbilicus, 
effuse, revolute, then perceptibly narrowed, produced, and extending to 
the acute, very thin, arcuate outer lip. (Translation.) 
Type in Academy, St. Petersburg. Type locality, Sudkiiste des Ochot- 
skischen Meeres. 
Range. Icy Cape, Arctic Ocean, south to the Aleutian Islands, and 
eastward to the Shumagin Islands. 
Genus AMAUROPSIS Morch, 1857 
Shell with canaliculated sutures. Scarcely distinct from Amanra. 
Type. Natica canalicnlata Gould. 
Distribution. Arctic, Point Barrow, Norway, Halifax, to Massa¬ 
chusetts Bay. Fossil at Montreal. 
Amauropsis purpurea Dali, 1871 
American Journal of Conchology, 7:124; Pi. 15, fig. 16. 
Shell elongate-globose, covered with a yellowish epidermis; color 
purple brown, when weathered, purplish white. Whorls four, inflated 
globose. Suture deeply canaliculated. Aperture more than half as long 
as the shell; outer lip thin; columella white, thickened, rounded; a thin 
callus on the inner lip. Umbilicus closed, or a mere chink. Spire very 
short, bluntly rounded. Sculpture of numerous close, very fine revolving 
grooves, and a few inconspicuous ridges. Long., 1.0; lat., .08 in. (Dali.) 
Type in United States National Museum. Type locality, St. Michael's, 
Norton Sound, Alaska. 
Range. Arctic coast westward from Bernard Harbor, to Point Bar- 
row and south to Plover Bay and Nunivak Island, Bering Sea. 
Family VANICOROIDAE 
Genus MEGALOMPHALUS Brusina, 1871 
Coquille mince, naticiforme ou auriforme; spire courte; tours arrondis; 
sommet regulier; ombilic tres grand, plisse; opercule corne, spiral. 
(Fischer.) 
Type. Megalomplialus azonus Brusina. 
Distribution. Mediterranean, west coast of North America. 
[ 736 1 
