GINGLYMACONCHA. VENERIDS. 309 
The animal with its tracheal tubes not extending beyond the 
valves; their extremities fringed ; the foot is rounded and ob- 
tuse. 3 ; 
Genus 51. Isocarpta. 
Shells inequivalve, cordiform and ventricose; their umbones 
distant from each other, divaricating and involuted ; the hinge 
with two teeth in each valve entering one another ; one is placed 
under the umbo in each valve; one lateral elongated lamella in 
each valve. 
1. Isocarp1A Cor. 
Shells cordate-globose, smooth, fulvous; the umbones 
whitish. Length two and three-quarters ; height three inches. 
Chama Cor, Lister, Conch. t. celxxv. f. 11; Linn. Syst. Nat. 
xu. 1137; Mont. Test. Brit. 134, 579; Flem. Edinb. 
Encycl. vii. 96; Lam. Hist. Nat. des Anim. sans Vert. vi. 
part. 1.31; Dill. Desc. Cat. 212; Turt. Conch. Dict. 32. 
Cardium humanum, Linn. Syst. Nat. x. 682. 
Cardita Cor, Brug. Encycl. Méth. 403. t. cexxxii. f. 1. a, 6, ¢, d. 
Isocardia globosa, Lam. Syst. des Anim. sans Vert. 118. 
Inhabits the Atlantic, European, Adriatic and Mediterranean 
seas ; it has been found at Bantry Bay, Ireland, and in the He- 
brides. 
STIRPS VII. 
Shells somewhat rounded or subglobose; umbones nearly 
central, prominent and recurved before; the cordiform im- 
pression imperfect ; both valves behind the umbones are more 
or less channelled. 
Genus 52. Loripss, Poli, Cuvier. 
Shells somewhat rounded, slightly convex; the cardinal 
ligament internal; the hinge with one simple straight tooth in 
the left, and two divaricating simple ones in the left valve ; 
