AI;N0LD— THE rALEONTOLOGY AND STUATIC.RAl'HY OF SAN PEDRO. 117 



" Shell adiierent, subequivalve. irregular, tlattened ; liiiit;e with two thick, divergent, elongated 

 lamella in the interior, corre.sjjonding with two long pits in the upper valve; upper valve with only 

 two muscular impressions; the pedal scar radiately striated"; surface with incremental lamin.e and 

 sonjetimes radial ridges. 



Part of tlie above description was taken iioiu Tryon. Tiiis species resembles 

 Annmid lampe, but may be (listiiiji;iiis]u'(l l)y its greater size and fewer imiscle-impres- 

 sioiis. Specimen identified by Dr. Dall. 



Rare in the npper San Pedro series of San Pedro, Crawfisli George's, ami 

 Deadman Island. Found also in the Pleistocene of the bliilT west of the bath-house, 

 at Santa Barbara. 



Licimj. — Unalaska to San Diego; Japan (Cooper). 



/'leimtocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold): 

 California; Oregon; Alaska (Dall): Santa Barbai-a (Arnold). 



Pliocene. — San Diego well (Dall). 



Miocene. — Sooke, Vancouver Island (Newcombe). 



Genus Anomia Linnf. 



Shell suborbicular, translucent, attached by a plug passing through a hole or notch in the 

 right valve; upper valve convex, smooth, lamellar, or striated; two byssal scars on the disk, main 

 byssal scar largest; foramen open, ample; hinge unarmed. 



Annmin ephippiurn LIuik'' is a characteristic species. 



39. Anomia lampe Gray. 



Anomia lampe Gray, Proc. Zool. Soc, 1849, p. 114. Carpenter, Brit. Assn. Rept., 1863, p. 646. 

 Gabb, Pal. Cal., Vol. II, 1869, p. 106. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, 

 p. 229. Keep, West Coast Shells, p. 163, 1892. Williamson, Proc. U. S. Nat. Mus., 

 Vol. XV, 1892, p. 194. Dai.l, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 785. 



Shell of medium size, suborbicular, thin, translucent and slightly pearly within ; surface of 

 left valve sculptured with fine, irregular, concentric lamellar lines and several prominent, irregular, 

 rounded, radiating ridges; interior of this valve with submarginal cartilage pit and four muscular 

 impressions; right or lower valve concave, with a deep rounded notch in front of the cartilage process. 



Dimensions. — Long, and alt. 48 mm.; diam. 9 mm. 



This species is variable both in regard to its shape and its sculpture, but ie 

 easily distinguishable by the thin, lamellar, translucent shell. Distinguishable from 

 A. limatula Dall by its smaller size and radial ridges. Specimens identified by 

 Dr. Dall. 



Common in the upper San Pedro series of San Pedro, Los Cerritos, Long 

 Beach, and Crawfish George's; rare in the lower San Pedro series of Deadman Island 



