74 



Pholas cruciger, Sowerby, Zool. Proc. p. 69, 1834. Catlow, Conch. Nomenc. 

 p. 3. D'Orbigny, Voy. Ainer. Merid. Moll. p. 490. Muller, Syn. Test. 

 Viv. p. 236. 

 •' crucigera, Pbilippi, Neiier Mollusken, iii. Pholas. t. 2, f. 4. 

 " crvcifera, Adams, Panama Shells, p. 301. Adams, Genera, ii. p. 335. 

 Chenu, Man. Conch, ii. f. 5. Fischer, Journ. Conch. 2d ser. iii. p. 48. 

 Gray, Ann. and Mag. Nat. Hist. 2d ser. viii. p. 381. Hanley, Desc. 

 Cat" p. 6. Jay, Cat. 4th ed. p. 10. Sowerby, Monog. Pholas. Thes. 

 Conch, ii. p. 489, t. 104, f. 24—26. 

 Coll. Acad. Nat. Sci. ; St. Croix, West Indies? Panama. Coll. Dr. J. C. Jay. 

 Coll. G. W. Tryon, Jr. 



This is a very distinct species, differing from all others in the genus by the 

 cruciform expansion of the dorsal margin. 



P. truncal a, Say, Journ. Acad. Nat. Sci. 1st ser. ii. p. 321. Adams, Genera, 



ii. p. 325. Catlow, Conch Nomenc. p. 4. DeKay, Moll. New York, 



D. 248, t. 34, f. 223 a b. Fischer, Journ. Conch. 2d ser. iii. p. 48. 



Gibbes, Tuomey's Geol. S. Carolina. Gould, Proc. Bost. ii. p. 81. 



Gray, Ann. and Mag. Nat. Hist. 2d ser. viii. p. 381. Hanley, Desc. 



Cat. p. 6, t. 9, f. 56. Jay, Cat. 4th ed. p. 10. Kurtz, Cat. Shells N. 



and S. Carolina, p. 3. Sowerby, Monog. Pholas, Thes. Conch, ii. p. 



488, t. 104, f. 29, 30. Stimpson, Shells New England, p. 25. Stimp- 



son, Check List E. Coast Shells. Wheatley, Cat. Shells U. S. p. 2. 



Coll. Acad. Nat. Sci. ; New Bedford, Mass., Long Island Sound, S. Carolina, 



Payta, Peru, Chili. Coll. Dr. J. C. Jay. Coll. Isaac Lea. Coll. G. W. Tryon, Jr. 



Mr. Sowerby wrongly refers for Say's description to "American Journal of 



Science, ii. p. 321." 



So late as 1845, Dr. Gould, in announcing to the Boston Society of Natural 

 History the occurrence of this species at New Bedford, Mass., remarked that it 

 was the only locality north of South Carolina ; it is now known to inhabit 

 almost the entire coast. 



P. truncata grows quite large on the northern coast, reaching three and a 

 half inches, as Dr. Gould informs me, in the vicinity of Sable Island. I had 

 some doubt respecting the locality " Chili" attached to a specimen in Coll. A. 

 N. S. until the recent discovery, amongst a mass of rubbish, of a large bottle 

 of shells, collected by Dr. W. S. W. Ruschenberger at Payta, Peru, which con- 

 tained a number of specimens of this shell and of Dactylina C h i 1 o e n s i s. The 

 west coast individuals are about the same size as our Southern specimens, 

 which they also resemble in form, being rather longer and narrower than those 

 from the New England States. 



P. 1 a t i s s i m a, Sowerby. 



P. latissima, Sow T erby, Proc. Zool. Soc. 1849, p. 162. Sowerby, Monog. 

 Pholas, Thes. Conch, ii. p. 489, t. 103, f. 15, 16. Adams, Genera, ii. 

 p. 325. Chenu, Man. Conchyl. ii. f. 4, 6. Fischer, Journ. Conchyl. 

 2d ser. iii. p. 48. Gray, Ann. and Mag. Nat. Hist. 2d ser. viii. p. 381. 

 Pbilippi, Neiier Conch, iii. Pholas, t. 2, f. 1. 

 P. patula, Gould, Bost Proc. ii. p. 214, May, 1850. Gould, Moll. U. S. Expl- 

 Exped. p. 384. Adams, Genera, ii. p. 325. Fischer, Journ. Conchyl. 

 2d ser. iii. p. 48. Jay, Cat. 4th ed. p. 10. 

 Jlab. — Manilla. Philippines. 

 Coll. Dr. J. C. Jay. 



Dr. Gould remarks, in the " Mollusca," that P. patula approaches, and may- 

 be identical with, Sowerby's species. The descriptions correspond, with the 

 exception of a vertical constriction which divides the valve of P. patula in the 

 middle, but which is not mentioned by Mr. Sowerby; nevertheless there is a 

 ^slight constriction of the valve represented in Mr. Sowerby's figure. There can 

 be no doubt of the identity of these shells. 



