PHOLAS. 39 



Pholas cordata. Gmelin, p. 3216. Wood's Conch, p. 85. 

 Pholas, No. 4. Schroeter Einl. hi. p. 544. t. 9. f. 22 to 



24 — the latter magnified. 

 Mytilus cordatus. Gmetin, p. 3361. ? 

 Enc. Method, t. 169- f. 8 to 10 — the latter magnified. 



Inhabits the Sea in Corallines. Schroeter. 



Shell about one third of an inch long, and nearly twice as broad, 

 slender, brittle, and of a dirty white colour ; the hinder part 

 is marked with fine elevated stria?, and the fore-part, except 

 a few ridges, is smooth ; the tooth is minute, and is con- 

 cealed by an oval shield, which from Schroeter's description, 

 appears to be a good deal like that of P. pusilla. I have 

 not had an opportunity to consult Spengler's work, but it 

 may be doubted from Gmelin's description of Mytilus cor- 

 datus, whether it was not taken from a specimen of this 

 species, in which the tooth had either been broken off or 

 overlooked. 



falcata. 9. Shell somewhat oval, variously stri- 

 ated, and the hiatus very large ; hinge with a 

 hooked tooth. 



Pholas falcata. Wood's Conch, p. 84. t. 16. f. 5 to 7. 



Inhabits 



Mr. Wood, who alone has noticed this species, says, it is ' dis- 

 tinguished by the singular conformation of its tooth, which 

 after curving from under the hinge in the usual manner, re- 

 turns again, so as to give it the figure of a pruning hook : 

 the aperture of the shell is very large ; at the base of which, 

 where the valves unite, there is a little projection, or nail, 

 which proceeds from the interior of the shell, and gives sta- 

 bility to the union.' From the figure, it appears to be near 

 half an inch long, and about three quarters of an inch broad, 

 and the external markings are similar to those of P. pusilla. 



hians. 10. Shell oval, transversely striated, with 

 the valves converging above, convex in the 

 middle, and wedge-shaped below ; hiatus 

 oval, and very large. 



Pholas hians. Chemnitz, x. p. 364. t. 172. f. 1678 to 1681. 

 Gmelin, p. 3217. Wood's Conch, p. 85. 

 Inhabits the West Indian Seas, burrowed in calcareous rocks 



and corallines. Chemnitz. 

 Shell about half an inch long, and nearly thrice as broad, white, 



and marked with transverse arched striae ; the teeth of the 



