Cardium. MOLLUSCA. CARDIADiE. 421 



Linn. Syst. i. 1122. Penn. Brit. Zool. iv. 90. t. 1. f. 37- Don. Brit. 

 Shells, t. vi. Mont. Test. Brit. 77. Turt. Biv. Brit. 180. t. xiii. f. 6, 

 7. — In sandy bays. 



Length nearly 4 inches ; light in proportion to its size ; ribs rather broad, 

 depressed with a rough or winged middle hue rising into lanceolate spines at 

 the retral side and compressed tubercles at the opposite, the furrows trans- 

 versely striated. The young of this shell is the Cardium ciliare of Linnaeus. 



432. C. tuberculatum. — Shell tumid, ponderous, with 21 



ribs, the posterior ones tubercular, the anterior ones scaly, and, 



together with interstices, rough with wrinkled striae. 



Linn. Syst. i. 1122. Don. Brit. Shells, t. cvii. f. 2. Mont. Test. Brit. 

 568. Turt. Biv. Brit. 181 — Western coast of England ; common in 

 Paignton Sands, Torbay, at low spring tides. 



Shell nearly the size of the last. " It is more solid and ponderous, of a 

 more globular shape, and running in a nearly straight line on the cartilage 

 side from the beaks ; the ribs are narrower, and the grooves are deeper, both 

 marked with strong irregular transverse striae ; the cartilage side is clothed 

 with rather sharp tubercles, which never extend into spines, and which, at 

 the opposite side, form thick transverse, scale-like plates : the colour is of a 

 deeper chesnut ; and the ribs on the inside extend only half wav towards the 

 beaks."— Dr Turton. 



— 433. C. echlnatum. — Tumid, thin, with 18 ribs, armed with 



numerous reflected spines. 



Pectunculus echinatus, List. An. Ang. 188. Conch, t. cccxxiv C. ech. 



Linn. Syst. t. 1122. Penn. Brit. Zool. iv. 90. Mont. Test. Brit. 78. 

 Don. Brit. Shells, t. cvii. f. 1. Turt. Biv. Brit. 183 Sandy bays. 



Less than the two preceding species, and more generally covered with 

 spines • these on the anterior side are large, and curved towards the cartilage 

 side. 



We have given separate stations to these three reputed species, in de- 

 ference to the authority of preceding authors, rather than from a conviction 

 that they are distinct. Indeed, judging from specimens, given us by Mon- 

 tagu and Dr Leach, and found more by ourselves, we can perceive that 

 none of the characters on which the distinctions are founded can be relied 

 on. The ribs vary from 16 to 21, from nearly smooth to coarsely wrinkled, 

 and the spines from sharp pointed and recurved, to broad and blunt or tu- 

 bercular. 



434. C. muricatum. — Shell elongate, slightly compressed; 



ribs 37, with numerous lateral tubercles. 



Pectunculus tenuis, List. Conch, t. cccxxii Cardium mur. Linn. Syst. 



i. 1123. 



A specimen of this shell, which I owe to the kindness of my friend Dr 

 Coldstream, and which was found by him at Leith, is upwards of an inch 

 and two-tenths in length, and about a tenth less in breadth ; whitish, tinged 

 with yellow, and blotched with brown ; the ribs are rounded, and the tuber- 

 cles, especially in the middle of the shell, are seated on the retral sides ; those 

 anteally are short, blunt, and on some of the ribs double, the retral ones are 

 more prominent ; the edge is strong and serrated ; the inside has a yellow 

 stripe from the beak, bordered on each side by a brown one ; the retral side 

 is brown and opake. We are disposed to consider the C. nodosum of Monta- 

 gu and Turton as this shell in a young state. 



