MYA. 163 



food ; and both the following species are eaten in some 

 parts of Britain and in North America. Thej are relished 

 also by animals ; and, in Greenland, according to Otho 

 Fabricins, are much sought after by the walrus, the arctic 

 fox, and various northern birds. 



Few mollusks are more widely distributed than our 

 native species of Mya, ranging as they do throughout the 

 arctic seas, owing to the same causes which we have no- 

 ticed as having brought about the extensive distribution of 

 the Saxicav(e. Their range southwards, however, is not 

 so great, for Cape Cod and New York respectively limit it 

 on the American shores, and neither of the species reach 

 the Mediterranean on those of Europe, although, during 

 the glacial period, the Mya truncata was once an inhabitant 

 of that sea, and has been found by Philippi fossil in very 

 recent tertiaries on the coast of Sicily. It is not impro- 

 bable that the original centre of the last-named species was 

 on the European side of the Atlantic, and that of M^a 

 arenaria on the American. The power each possesses in a 

 remarkable degree, of enduring changes in the amount of 

 saltness of the water, is no doubt a chief cause of their 

 wide distribution now. 



M, TRUNCATA, Liunseus. 



Valves, when adult, abruptly truncated behind. 



Plate X. f. 1, 2, 3, and (animal) Plate H. f. 1. 



List. Hist. Conch, pi. 428, f. 269. 

 Mya tnincaiu, Linn. Syst. Nat. p. 1112. — Penn. Brit. Zool. ed. 4, vol. iv. p. 

 78, pi. 41, f. 14. — PuLTENEY, Dorset, p. 27. — Donov. Brit. 

 Shells, vol. iii. p. 92.— Dorset Catal. p. 27, pi. 3, f. 1.— Mont. 

 Test. Brit. p. 32. — Linn. Trans, vol. viii. p. 35. — Turt. Conch. 

 Diction, p. 97. — Turt. Dithyra Brit. p. 31. — Flem. Brit. 

 Anim. p. 462. — Macgil. Moll. Aberd. p. 298.— Brit. Marine 

 Conch, p. 40. — Brown, Illus, Conch. G. B. p. Ill, pi. 45, f. 

 2, — Fabr. Fauna Grsenl. p. 404. — Chemn. Conch. Cab. vol. 



