212 BIVALVE SHELLS. 



Pctricola jiholadiformis, Jl'ood, Ind. Test. Suppl. 2. pi. 13. f. 49. 



I. yell, Mem. 8. G. Land. 183!>, p. 138. 



De Kay, Zool. Netv York, pt. 5. p. 228. i)l. 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, pi. 1. f. 14, 15. 



Hub. Canada ; New York, &c. 



14. Petricola serrata. 



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

 aequilaterali, squalide rufescente, extremitatibus obtusa, hiantc, 

 longitudinaliter costellata, in latere antico costellis majoribus 

 deuticulatis, in medio tennioribus, postice numerosioribus un- 

 dulatis, valvis tcuuibus, intus squaUde albis; sinu pallii elon- 

 gate, apice obtuso, basi latiore. 



Petricola serrata, Desk. Proc. Zool. Soc. 1853. 



Hub. Nova Zelandia. Coll. Cuming. 



15. Petricola nivea. 



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

 striata; cardiue lineari simulque dentato {Chemnitz). 



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



Gmel. p. 3358. no. 27. 



Dillw. Cat. i. .307. no. 17- 



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

 Petricola nivea, Gray, Ann. Phil. xxv. 



Hanley, Descr. Cat. p. 53. 



Hab. Insulse Nicobarieae (Chemnitz). 



16. Petricola fornicata. 



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

 ante, alba, longitudinaliter costata, costis anticis et medianis 

 subobsoletis, jiosticis elevatis, interstitia non ajquantibus, api- 

 cibus involutis ad ^ longitiulinis sitis ; dentibus duobus valvae 

 dextra; cardinalibus elongtitis, uncinatis. 



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

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



Hab. ? 



Differt a Pctr. dactylo. Sow., costis anticis obsoletis posticis 

 vero prominentibus [Philippi). 



17. Petricola linguatula. 



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

 postico elongato, subtruncato. 



