144 MACTRA. 





Shells ovate-oblong. 



glauca. 31. Shell sub-ovate, thin, marked with 

 fine transverse striae, forming wrinkles at the 

 anterior end, and with reddish longitudinal 

 rays. 



Mactra glauca. Born. Mus. p. 51. t. 3. f. 11 and 12. Gme- 

 lin, p. 3260. Donovan, iv. t. 125. Montagu Test. p. 

 571. Maton and Racket, in Lin. Trans, viii. p. 68. 

 Mactra helvacea. Chemnitz, vi. p. 234. t. 23. f. 232 and 



233. 

 Etic. Meth. t. 256 f. 1. 

 Inhabits the coasts of Spain and Portugal. Chemnitz. Found 

 on Hayle Sands, in Cornwall, by Miss Pocock. Donovan. 

 Shell usually two inches and a half long, and three and a half 

 broad, but sometimes three inches long, and more than four 

 and a quarter broad ; it is striated transversely, and wrinkled 

 at the anterior end ; of a dirty white colour, marked with 

 reddish longitudinal rays, which however are not observable 

 in the specimen figured by Born, and which appears to be 

 covered with a thin epidermis. 



pellucida. 32. Shell sub-ovate, thin, pellucid, 

 unequally striated transversely, and gaping 

 at the anterior end. 



Mactra pellucida. Chemnitz, vi. p. 235. t. 24. f. 234. 



Gmelin, p. 3260. 

 Mactra, No. 11. Schroeter Einl. iii. p. S5. 



Inhabits the coasts of Guinea. Chemnitz. 



Shell about an inch and a quarter long, and near two inches 

 broad; thin, pellucid, brittle, white, and somewhat pro- 

 duced and gaping at the anterior end. 



fragilis. 33. Shell ovate-oblong, pellucid, thin, 

 and finely striated transversely ; anterior end 

 angulated and gaping. 



Mactra fragilis. Chemnitz, vi. p. 236. t. 24. f. 235. Gme- 

 lin, p. 3261. 



Mactra dealbata. Solander's MSS. Pulteney's Dorset 

 Cat. p. 31. Montagu Test. p. 95. t. 5. f. 1. Maton 

 and Racket, in Lin. Trans, viii. p. 68. t. 1. f. 10. Dor- 

 set Cat. p. 32. t. 7. f. 7. 



