CLASS PELECYPODA 
109 
ately elevated, capped by the prodissoconch; internal margins smooth, the 
posterior adductor scar larger; hinge as described under the genus, with 
no external ligament; texture of shell porcelaneous and rather solid. 
Length, 2.3; height, 1.6; diameter, 1 mm. (Dali.) 
Type in U. S. N. M., No. 221199. Type locality, near the south 
Coronado Island, in 3 fathoms. 
Range. Coronado Islands, Lower California. 
Family CRASSATELLITID2E. 
Genus CRASSATELLITES Kruger, 1823. 
Shell solid, inequilateral, slightly inequivalve, usually subtrigonal, the 
posterior end longer; valves closed, the ligament and resilium adjacent and 
internal; hinge of three cardinals in the right valve, of which the posterior 
is more or less effaced by the resilium, and two in the left valve; the 
anterior edge of the right and the posterior edge of the left hinge-margin 
grooved to receive the edge of the opposite valve, which is beveled to 
serve as a lateral lamina; sculpture chiefly concentric and often obsolete 
except near the umbos. (Dali.) 
Type. Crassatellitcs sinuata Kruger. 
Distribution. West Coast of North America. 
Range in time. From the Miocene, North America. 
Crassatellites fluctuatus Carpenter, 1864. 
Sup pi. Rep. Brit. Assoc., 1864. p. 642. Proc. Cal. Acad. Set., 3 :209. 
A. t. valde planata, ovoidea, costis concentricis valde distantibus, angus- 
tis, undulatis, ornata; marg. dors. post, subrecto, ant. concavo, lunula longa, 
parum impressa; ventr. satis rotundato; ant. valde rotundato; post, sub- 
quadrato; intus, v, dextr., lamina cardinali planata; dent. card. i. inter 
fossas ant. parvam, post, triangularem, extante; dent. lat. ant. acutiore, 
satis elongato, post, nullo; cicatr. adduct, ovalibus, postica callo definita; 
margine baud crenato; sulco ligamenti externi elongato. Long., .33; 
lat., .26. (Carpenter.) 
Described as Astarte fluctuata. 
Type in California State Collection, No. 1060. Type locality, Catalina 
Island, California. 
Range. Santa Barbara Island to San Pedro, California. 
Genus CRASSINELLA Bayle. 
Shell obliquely lengthened, subquadrangular. 
Type. Astarte obliqua Deshayes. 
Distribution. Pacific, California. 
