GINGLYMACONCHA. VENERID. 305 
Genus 47. Cauista, Poli. 
The shells roundly heart-shaped, their umbones very much 
reflexed ; the cardinal ligament nearly buried ; the hinge with 
two teeth in each valve; those in the right valve nearly equal, 
the hinder one ‘in the left valve much smaller than the anterior 
one. 
The tracheal tubes equal, half-jomed together; the foot 
lance-shaped. 
1. CALISTA VERRUCOSA. 
Shells concentrically grooved; the margins of the grooves 
thin, refiexed and transversely striolated, behind undulately 
rough. Epidermis dirty white, striolated with very slender, 
longitudinal, divaricating, fuscous or reddish-brown streaks. 
Length two and a half; height two and a half inches. 
Venus verrucosa, Lister, Conch. t. cclxxxiv. f. 122; Petiv. 
Gaz. t. xc. f. 7; Linn. Syst. Nat. 1130. no. 116; Bor- 
lase, Cornw. t. xxvii. f. 32; Pult. Cat. Dorset. 33. t. vil. 
f. 1; Mont. Test. Brit. 112, 574; Flem. Edinb. Encyel. 
vil. 94; Dill. Desc. Cat. 163 ; Lam. Hist. Nat. des Anim. 
sans Vert. v. 586; Turt. Conch. Dict. 231. 
Venus Erycina, Penn. Brit. Zool. iv. 94. t. liv. f. 48. 
Pecten strigatus, Da Costa, Brit. Conch. 185. t. xii. f. 1. 
Pecten membranaceus, Da Costa, Brit. Conch. 193. t. xiii. f. 4. 
Venus cancellata, Donov. Brit. Shells, t. Ixiv., exv. 
Inhabits the European seas in deep sandy bottoms. 
2: “CALISTA CASINA. 
Shells concentrically ridged; the ridges distant from one 
another, reflexed and gradually decreasing behind, and with 
the interstices concentrically striated. Epidermis reddish- 
brown. Length and height two inches. 
Venus casina, Linn. Syst. Nat. xii. 1130. no. 117; Gmel. 
Syst. Nat. 3269 ; Lam. Hist. Nat. des Anim. sans Vert. 
