212 BIVALVE SHELLS. 



Petricola pholadiformis, Wood, Ind. Test. Suppl. 2. pl. \'6. f. 49. 



Lyell, Mem. S. G. Lond. 1839, p. 138. 



De Kay, Zool. New York, pt. 5. p. 228. pl. 28. f. 282. 

 Petricola fornicata, Say, Journ. Acad. Nat. Sc. Phil. ii. 319. 



Russell, Essex Co. Soc. Journ. i. 55. 

 Petricola peruviana, Jay, Cat. of Shells, 1839, pl. 1. f. 14, 15. 



Hab. Canada ; New York, &c. 



14. Petricola serrata. 



P. testa elongato-transversa, angustissima, cylindracea, valde in- 

 aequilaterali, squalide rufescente, extremitatibus obtusa, hiante, 

 longitudinaliter costellata, in latere antieo costellis majoribus 

 denticulatis, in medio tenuioribus, postice numerosioribus un- 

 dulatis, valvis tenuibus, intus squalide albis; sinu pallii elon- 

 gato, apice obtuso, basi latiore. 



Petricola serrata, Desh. Proc. ZooL Soc. 1853. 



Hab. Nova Zelandia. CoU. Cuming. 



15. Petricola nivea. 



P. testa ovali, nive candidiori, subdiaphana, longitudinahter dense 

 striata; cardine lineari simulque dentato {Chemnitz). 



Mytilus niveus, Chemn. Conch. viii. 154. pl. 82. f. 734. 



Gmel. p. 3358. no. 27. 



Dillw. Cat. i. 30/. no. 17- 



Wood, Ind. Test. pl. 12. f. 16. 

 Petricola nivea, Gray, Ann. Phil. xxv. 



Hanley, Descr. Cat. p. 53. 



Hab. Insulae Nicobaricae {Chemnitz). 



16. Petricola fornicata. 



P. testa elongata, subcylindrica, utrinque rotundata, postice hi- 

 ante, alba, longitudinaliter costata, costis anticis et medianis 

 subobsoletis, posticis elevatis, interstitia non aequantibus, api- 

 cibus involutis ad ^ longitudinis sitis ; dentibus duobus valvae 

 dextrae cardinalibus elongatis, uncinatis. 



Petricola fornicata, So.y, Journ. Acad. Nat. Sc. Phil. ii. 319. 

 Petricola costata, Phil. Zeits.fur Malak. 1848, p. 163. no. 32. 



Hab. ? 



Diltert a Petr. dactylo, Sow., costis anticis obsoletis posticis 

 vero prominentibus {Philippi). 



17. Petricola linguatula. 



P. testa parva, transversim oblonga ; latere antico brevissimo ; 

 postico elongato, subtruncato. 



