88 TESTACEOUS MOLLUSCA. 
C. Incrassara. Desh. in Lam. 7. p. 257. Solid, triangular, 
sub-cordiform, inflated; chesnut brown, quite smooth except at the 
beaks, which have transverse wrinkles ; slightly inflexed on one side ; 
margin usually denticulated ; hinge with two strong teeth, one in 
the right valve minute. — Mediterrancan ? 
C. Castanea. Say. Am. t. 1. f. 1.—Gould. Mas.—Venus. 
C. Say. I. A. N. S. Rounded, depressed, solid, and irre- 
gularly striated, with a chesnut cuticle and acute beaks; Iunule 
oval-oblong and depressed: within white, with the margins finely 
crenulated, and the teeth of one valve unequal. 1.—New Jersey. 
C. Boreatis. Gray. Ann. Phil. 25.—Venus B. Lin. 1134.? 
—D.p. 198.—Ch. f. 412, 3, 4. Rounded ovate, both slopes sub- 
truncated, flattish, transversely striated, white under a reddish 
brown cuticle, always decorticated at the beaks. 1..14.—W. 
Europe? 
C. Monracur. Gray. Ann. Phil. 25.—Venus Compressa. 
Mont. t. 26. f.1.—D. p. 167.—W. t. 7. f. 19.—Cyprina. C. 
Turt. Biv. t.11.f. 20. to 23. Sub-triangular, posteriorly rounded, 
anteriorly but slightly so, obsoletely and irregularly grooved trans- 
versely, white under a brown cuticle: the depression in front of 
the beaks, which are very prominent and inclining, sudden. 3. 
— Scotland. 
C. Crenata.—Nicania. C. Gray in Parry Sup. Oval- 
elliptical, with regular concentric furrows, pale yellowish greeen : 
umbones sub-central, lunule oblong lanceolate: in one valve a bifid 
cardinal tooth, in the other two simple ones, two rudimentary small 
lateral laminze in each: margin crenated.— LV. Pole. 
C. Lacrna.—Astarte. L. Brod. and Sow. Z. J. 4.— Beechey. 
Zool. t. 44. f. 12.— Gould. Mas. p. 81. Obovate, compressed, 
posteriorly shorter, the anterior dorsal margin depressed: dull, 
with a thick dark cuticle, distinctly marked with concentric lines of 
growth : inside white, margins quite entire. 1}3..14.—Jcy Cape. 
C. Artica. Gray. in Parry Sup. Roundish ovate, convex, 
white under a black shining finely concentrically striated cuticle : 
umbones rather prominent, slightly grooved concentrically ; lunule 
oblong-ovate, deep, anteriorly lanceolate: in one valve a strong 
simple cardinal tooth, two diverging ones in the other, lateral 
laminz two in each valve, the anterior remote and small: edge 
entire. 11..13.— N. Pole? 

' Compare with these the ASTARTE Cyprinoipes of Duval, in 
Rev. Z. Cuv. 1841. 
