80 PHOLAS. 



The figure of this shell by Gualtieri is so indifferent 

 as hardly to deserve a place among the synonyms. 



RIBBED PIERCER. 

 PL 15. /. 1, 2. Mrs. Mawe. 



4. Pholas costata. Ph. testa ovata, costis elevatis striata. Linn. Syst. 



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

 Shell oval, with raised striated ribs. 

 Testa lata, ventricosa, transverse striata, costis longitudinalibus, extimis 



acutis remotioribus. Born, Test. p. 15. 

 List. Conch, t. 434. f. 277. Gualt. Test. 1. 105. f. G. Knorr, Vergn. 2. 



t. 25. f. 4. Ckemn. Conch. 8. f. 863. Favanne, pi. 60. c. 1. Ency- 



clop. Method, pi. 169. f. 1, 2. 



This shell is of an oblong oval shape, gaping at both 

 ends. It is a strong species, ribbed regularly from one 

 end to the other ; the ribs are oblique and somewhat 

 spinous, especially at the broad end, where they are 

 farther apart, and scalloped at the margin. The hinge 

 is reflex, and has an additional fold which is spread 

 thinly on the back of the shell ; there is a strong curved 

 tooth in each valve ; the slope from the hinge towards 

 the tip of the shell is free from ribs. This shell is 

 of a cream colour, and measures from three to six 

 inches from end to end. 



It inhabits America, and, according to Linnaeus, is 

 found among rocks in the South of Europe ; but the 

 finest specimens are from the East Indies. 



