320 GINGLYMACONCHA: VENERIDZ. 
Test. Min. Rar. f. 38; Gmel. Syst. Nat. 3255; Pult. Cat. 
Dorset. t. u. f. 11; Mont. Test. Brit. 82; M. & R. Trans. 
Tinn. Soe. vi. 61; Flem. Edinb. Encycl. vii. 91; Lam. 
Hist. Nat. des Anim. sans Vert. vi. part. 1. 14; Wood. 
Gen. Conch. i. 212; Dill. Desc. Cat. 114; Turt. Conch. 
Dict. 31. 
Cardium pygmeum, Donov. Brit. Shells, t. xxxu. f. 3. 
This species is occasionally found on the southern coasts of 
Devon and Ireland. Salcombe Bay, Col. Montague; Falmouth, 
Mr. J. Cranch; Weymouth, Dr. J. Goodall; Cork Bay, J. 
Drummond, Esq. ; Bantry Bay, Miss Hutchings; Dingle Bay, 
myself. 
8. CARDIUM LEVIGATUM. 
Shells very high, short, smooth, sculptured anteriorly and 
posteriorly with very obsolete ribs and very fine divaricating 
lines ; the epidermis yellowish-brown or olive-brown. Length 
two inches ; height two inches and a half. 
Cardium levigatum, Lister, Anim. Angl. t. v. f. 32 ; Conch. 
ecexxxul. f. 169; Pet. Gaz. t.xciu.f. 10; Linn. Syst. Nat. 
xn. 1123. no. 88; Penn. Brit.. Zool. iw. 91. tl dose 
Pult. Cat. Dorset. 31. t. vii. f. 6; Donov. Brit. Shells, 
t. Ixxx.; Mont. Test. Brit. 80; Flem. Edinb. Encycl. vii. 
91; Wood, Gen. Conch. 1. 222. t. liv. f. 1; Dill. Dese. 
Cat.123. J 
Cardium levigatum, Turt. Conch. Dict. 31. 
Cardium fluviatile, Gmel. Syst. Nat. 3255. 
This species is extremely common in the British seas, but 
is found most abundantly in estuaries. 
FAMILY XI. UNIONID. 
Shells with the valves elongated, equivalve ; the umbones 
anterior ; the ligament external and hinge-shaped ; the epi- 
dermis leathery-membranaceous. 
