*266 AMERICAN JOURNAL 



3. P. COgnata, C. B. Adams, Panama Shells, 286, 1852. 



Panama. 



4. P. concinna, Sowerby, Zool. Proc. 46, 1834. 



Thes. Conch, ii, 753, t. 166, f. 3, 1855. 



Monte Christi. 

 P. costata, Phil. = P. dactylus, Sowb. 



P. costellata, Lam. = P. lithophaga. 



5. P. cultellus, Deshayes, Zool. Proc, 1853. 



Sowb. Thes. Conch, ii, 772, t. 166, f. 2, 5, 1855. 



Ceylon. 

 P. dactylus, Say = P. pholadiformis, Lam. 



6. P. dactylus, Sowerby, Genera of Shells, f. 3, 1820-24. 



Thes. Conch, ii, 772, t. 166, f. 4, 1855. 

 P. costata, Philippi, Zeit. Mai. 163, 1848. 



Panama, So. America. 



7. P. denticulata, Sowerby, Zool. Proc. 46, 1834. 



Thes. Conch, ii, 773, t, 166, f. 6, 7, 1855. 

 P. ventricosa, Deshayes, Zool. Proc. 1853. 



Payta, Peru ; Mazatlan (Carpenter). 



P. discors, Sowerby, Zool. Proc. 46, 1834. 



(Not identified by Sowerby, Jr., in Thes. Conch. 



8. P. elliptica, Sowerby, Zool. Proc. 46, 1834. 



Thes. Conch, ii, 774, t. 166, f. 10, 1855. 

 P. solida, Sowerby, Zool. Proc. 46, 1834. Thes. Conch, ii, 

 774, t. 166, f. 9, 1855. Payta, Peru. 



9. P. elegans, Deshayes (Venerupis), Zool. Proc, 1853. 



Sowerby, Thes. Conch, ii, 773, t. 166, f. 8, 1855. 



Hab.—? 

 P.fornicata, Say = P. pholadiformis. 



P.gibba, Middendorff = P. nivea. 



P. gracilis, Deshayes = P. pholadiformis. 



P. hyalina, Deshayes = P. lithophaga. 



P. linguatella, Deshayes. 



10. P. lithophaga, Retz. (Venus.) Trans. Turin, v, 11, f. 1, 2. 



Sowerby, Thes. Conch, ii, 774, t. 166, f. 18, 19, 1855. 

 P. striata, Lamarck, Anirn. sans Vert, v, 504, 1818. 

 P. costellata, " " " " 1818. 



P. rocellaria, " " " " 1818. 



P.ruperella, " " " " 1818. 



Mya deeussata, Dillwyn, Cat. 46, 1817. 



