PHOLAS. 79 



Inhabits the Indian ocean about Siam and Tran- 

 quebar. 



The accessory valves so readily fall off, that the shell 

 is very rarely found perfect. It is figured entire, how- 

 ever, by Chemnitz in a vignette, vol. 8. p. 347. 



WHITE PIERCER. 

 PL 14. /. 3, 4. 



3. Pholas Candida. Ph. testa oblonga, undique striis decussatis muri- 



cata. Linn. Syst. Nat. ed. 12. p. 1111. Linn. Gmel. p. 3215. 

 Shell oblong, and covered with prickly decussated striae. 

 List. Anim. AngJ. t. 5. f. 39. Append, t. 2. f. 4 — 6. Conch. 



t. 435. f. 278. Gualt. Test. t. 105. f. E. Chem. Conch. 8. t. 101. 



f. 86 1. Penn. Brit. Zool. 1812. vol. 4. pi. 42. f. 2. Donov. Brit. 



Shells, pi. 132. Mont. Test. Brit. p. 25. Linn. Trans. 8. p. 31 . 



This is a very brittle shell, decussated in all parts, 

 except close to the cartilage on the back. The broad 

 end nearly round, and set from the hinge to the 

 margin, with several rows of prickles. The striae on 

 the other parts of the shell are all prominent, but less 

 elevated than those at the broad end; hinge smooth, 

 white, and reflex; a single accessory valve of a lancet 

 shape on the back, but none on the connecting mem- 

 brane below the hinge, as in the P. Dactylus. Inside 

 smooth, and glossy white, with a thin curved tooth in 

 each valve ; the thick lip above each tooth terminates in 

 a horizontal, folded process, curved towards the carti- 

 lage. Colour yellowish white. Breadth, or from end 

 to end, from one inch to two and a half, or three inches. 



Inhabits the European and American seas. It is not 

 an uncommon shell on some parts of the British coast, 

 but is not often found perfect. 



