194 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Spisula hemphilli Dali, 1894. 
Plate 46 and plate 50. 
Nautilus, 7:137; pi. 5, fig. 2. 
Shell large, thin, inflated, sub-equilateral, creamy white with a yellow, 
thin epidermis, which over the body of the shell in young shells is beauti¬ 
fully, evenly, concentrically striated and on the posterior dorsal area is 
irregularly wrinkled, with an elevated raphe of epidermis at the margin 
of the area; beaks rather prominent, the anterior end of the valves longer 
than the posterior; posterior dorsal slope excavated; lunule obscure, 
escutcheon marked by prominent, elevated, radial lines of epidermis; the 
dorsal margin pouting in front of the ligament, the posterior slope convex, 
the posterior flexure faint, but marked by a recession of the ventral border 
of the valves, which gape but very little and not at all in front; anterior 
end rounded, but smaller than the posterior; ventral border arcuate; hinge 
and pallial sinus much as in the last species, except that the sinus is 
somewhat smaller and less depressed. Length, 120; height, 93; diameter, 
50 mm. (Dali.) 
Type in U. S. N. M. Type locality, San Diego, California. 
Range. San Pedro to San Diego, California. In the Pleistocene at 
San Pedro, California. 
Spisula catilliformis Conrad, 1867. 
Plate 24. 
Amer. Jour. Conch., 3:193. Nautilus, 7; pi. 5, fig. 3. 
Shell large, thin, whitish or straw color, irregularly, concentrically 
striated, with a gray, wrinkled epidermis, inflated short-oval sub-equilateral 
valves and closely adjacent inconspicuous beaks; anterior end of shell 
evenly rounded in front, a little shorter than the posterior end; lunule 
narrow, impressed, escutcheon narrow, longer, rather obscure; posterior 
end of valves rounded, slightly compressed and with a narrow gape when 
closed; hinge resembling that of M. polynuma Stimpson, but more con¬ 
centrated, cartilage pit large, rather produced; posterior muscular im¬ 
pression larger, pallial sinus rather large, rounded in front. There is a 
faint posterior flexure of the valves and a feeble marked area above it, 
on which the epidermis is more conspicuous. (Conrad.) 
Type locality, Panama. 
Range. Neah Bay, Washington, to San Diego, California. In the 
Pleistocene at Ventura, San Pedro and San Diego; and the Pliocene at 
San Diego, California. 
