88 TKSTACEOUS MOLLTJSCA. 



C. Incrassata. Desk, in Lam. 7- p. 257. Solid, triangular, 

 sub-cordifonn, inflated ; chesnut brown, quite smooth except at the 

 beaks, which have transverse wrinkles ; slightly inflexed on one side ; 

 margin usually denticulated ; hinge with tw^o strong teeth, one in 

 the right valve minute. — 3Iediterrariean? 



C. Castanea. Sai/. jhn. t. 1. /. 1. — Gould. Mas. — Venus. 

 C. Soy. I. A. N. S. Rounded, depressed, solid, and irre- 

 gularly striated, with a chesnut cuticle and acute beaks ; lunula 

 oval-oblong and depressed : within white, with the margins finely 

 crenulated, and the teeth of one valve unequal. 1. — Ne7V Jersey. 



C. BoREALis. Gray. Ann. Phil. 25. — Venus B. Lin. ll'M.t 

 — D. p. 198.— CA./. 412, 3, 4. Rounded ovate, both slopes sub- 

 truncated, flattish, transversely striated, white under a reddish 

 brown cuticle, always decorticated at the beaks. l.,\^. — N. 

 Europe ? 



C. MoNTAGui. Gray. Anji. Phil. 25. — Venus Compressa. 

 Mont. t. 26./. 1.— Z>. p. 167.— TF. t. 1 . f. 19.— Cyprina. C. 

 Turt. Bir). t.' I \.f. 20. to 23. Sub-triangular, posteriorly rounded, 

 anteriorly but shghtiy so, obsoletely and irregularly grooved trans- 

 versely, white under a brown cuticle : the depression in front of 

 the beaks, which are very prominent and inchning, sudden. ^. 

 — 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 laminae in each : margin crenated. — N. Pole. 



C. Lactea. — AsTARTE. L. Brod. and Sow. Z. J. 4. — Beerhey. 

 Zool. t. 44. /. 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 

 gi'owth : inside white, margins quite entire. 1|^..1|^. — Icy 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, tw^o diverging ones in the other, lateral 

 laminae two in each valve, the anterior remote and small : edge 

 entire. \\.. \\.—lSi. Pole.^ 



* Compare with these the Astarte Cyprinoides of Duval, in 

 Uev. Z. Cue. 1841. 



