22 CARDIADiE. 



C. NODOSUM, Turton. 



Small, never porcelain wliite, nor marked with coloured bands ; 

 ribs about twenty-seven in number, all armed with scaly tu- 

 bercles. 



Plate XXXII. fig. 7. 



Cardium 7iodosuin, Turton (not Montagu, Maton and Rackett, nor Wood) 

 Dithyra Brit. p. 186, pi. 13, f. 8.— Hanl. Recent Shells, 

 136, suppl.pl. 17, f. 44 (copied from last). — Loven, Moll. 

 Skandin. p. 36. — Reeve, Conch. Iconica, Cardium, pi. 22, 

 f, 128. 

 „ scabntm, Philippi, Moll. Sicil. vol. ii. pi. 14, f. 16. — Hanl. Recent 

 Shells, Suppl. pi. 17, f. 43. 



The shape is suborbicular, subrectangular at the beaks, 

 and rather wide below. The valves are moderately ventri- 

 cose, the convexity being rather evenly diffused, and gradu- 

 ally diminishing from the umbones ; they are more or less 

 strong, opaque, and usually of an uniform rather squalid 

 white or pale cream colour, and very rarely stained with 

 orange or pink upon the umbonal region. The surface is 

 entirely radiated over with about twenty-eight narrow 

 moderately-elevated ribs, separated by still narrower deep- 

 ly-cut interstices : these ribs are most crowdedly set with 

 squamular tubercles, which, in different individuals, vary 

 in shape, from suborbicular to linear sublunate, and have 

 a tendency to become depressed in front, and spinous be- 

 hind upon the posterior area ; which latter is distinctly flat- 

 tened, but its commencement is not indicated by any 

 peculiarly sharp angulation. The ventral margin is mode- 

 rately arcuated, and ascends in front, where the convexity 

 is more decided. The degree of convexity and of declina- 

 tion in the dorsal edges is but trifling ; the hinder one is 

 decidedly the more sloping. The sides are nearly equal, 

 the front being, in general, rather the shorter, and being 



