124 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
U.S. Fish Commission Station 4423, between Santa Barbara and San 
Nicolas Island, California, in 216-339 fathoms. 
Range. Off Esteros Bay, California, and south to Gulf of California. 
Natica aleutica Dali, 1919 
Proceedings of the United States National Museum, 56:352. Proceedings of the 
Biological Society of Washington, 32:251. 
Shell large, round, slightly flattened in front of the suture, pinkish- 
white, covered with a light brownish, spirally minutely striated periostra- 
cum, a white area surrounding the umbilical region; whorls six or more, 
the nucleus minute, aperture lunate, simple, the body with a coat of enamel, 
the umbilicus completely, smoothly filled with a semilunate pad of callus; 
operculum solidly calcareous, smooth, with an obscure swelling centrally. 
Height, 46; diameter, 40 mm. (Dali.) 
Type in United States National Museum, No. 217156. Type locality, 
Unalaska, Aleutian Islands. 
Range. North end of Nunivak Island, Bering Sea, to Aleutian chain 
to Puget Sound; Kamchatka to Japan. 
Genus POLINICES Montfort, 1810 
Shell oval or suboval, solid, smooth, spire short, sharp; aperture semi¬ 
circular, inner lip oblique, callous, the callus extending into the umbilicus. 
Operculum corneous. Color usually white, sometimes colored but not 
banded or spotted. (Tryon, Manual of Conchology.) 
Type. Polinices uber Valenciennes . 
Distribution. West coast of North America, Japan, Philippines, 
Mauritius. 
Subgenus Euspira Agassiz, 1842 
Polinices acosmitus Dali, 1919 
Proceedings of the United States National Museum, 56:352. 
Shell white with a minutely spirally banded yellow brown periostracum 
and about four whorls, the nucleus defective; suture distinct, the whorl 
in front of it a little impressed; axial sculpture of fine silky incremental 
lines; there is no spiral sculpture; aperture semilunar, oblique, the outer 
lip thin, the body with a coat of enamel reflected over the umbilical region 
in a flat pad as in Cryptonatica, the pillar lip somewhat thickened. Height 
of shell, 16; of aperture, 13; diameter, 15 mm. (Dali.) 
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