112 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Er Schale nach gerath man in Zweifel, ob man dieses Thier zu den 
Fatellen bringen diirfe, oder ob es nich vielmehr ein Capulus sei; von 
letzterem eschlechte entfernt sicli ubrigens die Schale noch mehr als von 
den Patellen durch ihre grosse Dunne, vermoge welcher sie sogar die 
Velutinen ubertrifft, und durch den unbedeutender und kaum hakig zu- 
ruckgebogenen Wirbel. Die Maassverhaltnisse der Schale sind folgende. 
Long., 22; latit., 19; altit., 10 mm. (Middendorff.) 
Type in St. Petersburg? Type locality, Okhotsk Sea. 
Range. Arctic Ocean to Pribilof Islands, Bering Sea, and the Okhotsk 
Sea. 
Thin, transparent, radiately striate or smooth except growth lines, 
whitish or yellowish, faintly striate with darker color, under a thin yel¬ 
lowish epidermis, base rounded, apex small, inclined. (Tryon and Pilsbry, 
Manual of Conchology.) 
This is the description of C. radiatus Sars, which is given as the same 
as Piliscus commodns. 
Family HIPPONICIDAE 
Genus HIPPONIX Defrance, 1819 
Shell thick, obliquely conical, apex posterior; base shelly, with a horse¬ 
shoe-shaped impression, corresponding to that of the adductor muscle. 
(Woodward, Manual of the Mollusca .) 
Type. Hipponix cornucopia Defrance. 
Distribution. West Indies, Persian Gulf, Philippines, Australia, Pa¬ 
cific, West America. Fossil, U. chalk .... Britain, France, North 
America. 
Hipponix antiquatus Linnaeus, 1767 
Systerna Naturae , 12th ed., Tryon, Manual of Conchology , 8:134; PI. 40, figs. 93-99. 
Testa integra oblonga imbricata, vertice postico recurvato. Testa opaca, 
lactea, multum imbricata. Apertura ovata, apex posticus, recurvus. (Lin¬ 
naeus.) 
Shell entire, oblong, imbricate, recurved in the rear. Shell oblique, 
milky, strongly imbricate. Aperture ovate, apex posterior, recurved. 
(Translation.) 
Type in Linnaeus Society, London. Type locality ? 
Range. Crescent City, California, to Panama, and the Galapagos 
Islands. Also Atlantic. 
[714 1 
