CLASS PELECYPODA 
65 
deep, rounded notch in front of the cartilage process; disk with a single 
(adductor) impression. (Linnaeus.) 
Type. Anomia ephippium Linnaeus. 
Distribution. North America, Britain, Black Sea, India, Australia, 
W. Am. Icy Sea. 
Range in time. Oolite. 
Anomia peruviana Orbigny, 1846. 
Proc. Zool. Soc., 1846, p. 117. This is the shell that has been called A. lampe Gray, 
1849, Voy. Amer. Mer., p. 673. Philippi. Abb. u. Beschr., 3; pi. 1, fig. 2. 
Shell yellowish green, radiately costated; internal green. Upper mus¬ 
cular scar large, squarish; lower two rather smaller, subequal, near 
together and to the upper scar, and nearly on the same line; sinus in 
lower valve very large. Length, 36; height, 40; diameter, 6 mm. 
(Orbigny.) 
Type in Museum Cuming. Type locality, California. 
Range. San Pedro, California, to Peru, and Galapagos Islands. In 
the Pleistocene at Ventura, San Pedro and San Diego, California. 
Genus PODODESMUS Philippi, 1837. 
Valves radiately grooved; perforation of lower valve moderate, firmly 
embracing and enclosing the plug. (Tryon. S. S. Conch.) 
Type. Pododesmus decipiens Phil. 
Distribution. West Indies, Britain, New Zealand, California, Bering 
Sea, Ochotsk. 
Pododesmus macroschisma Deshayes, 1839. 
Plate 26, figs, la, lb. 
Revue Zool. Soc. Cuvierienne, p. 359. Guerin, Mag. de Zool., 1841; pi. 34. 
Shell ovate, rather solid, radiately rudely plicately ribbed, ribs very 
irregular, here and there swollen and bifurcated; yellowish white; per¬ 
foration very large. This fine species is distinguished by a broadly ribbed 
growth, the ribs being very irregular. (Conch. Iconica.) 
Type in Cuming Museum. Type locality, Kamchatka. 
Range. Southern Bering Sea, from the Pribiloff Islands, and Una- 
laska, to San Diego. Also Japan. In the upper Miocene of Sooke, Van¬ 
couver Island, Pliocene of San Diego; Pleistocene of California, Oregon, 
and Alaska. 
Family MYTILIDZE. 
Genus MYTILUS Linnaeus, 1758. 
Shell wedge-shaped, rounded behind, smooth in the typical species; 
umbones terminal, pointed; hinge teeth minute or obsolete; pedal muscular 
