81 



Pholas fragilis, Sowerby, Proc. Zool. Soc. p. 161, L849. Sowerby, Monog. 

 Thes. Conch, ii. p. 488, t. low, f. 92, 93, 1849. 



/.' • fragility Fischer, Journ. Conch. 2d Ber. iii. p. 19. 



Barnia fragilis, Gray, Ann. and Mag. Nat. Hist. 2d ser. viii. p. 382. 



Hob. — Manilla. Philippines. 



Coll. Acad. Nat. Sci. Coll. J. C. Jay, M. D. Coll. G. W. Tryon, Jr. 



The Pholas fragilis of Sowerby is undoubtedly identical with M a n i 1 1 e n s i s. 

 This species dill'ers from B. s i m i 1 i s in having a different shaped dorsal plate, 

 which is also much smaller in proportion to the valves, which are narrower, 

 with the umbones placed nearer the anterior end ; and by the extension of the 

 ribs over the whole posterior surface, which is quite plain in B. similis. 

 Barnea p a r v a is a wider shell, with the umbones nearer the centre. 



B. P a r v a, Pennant. (Sp.) 



Pholas p arva, Pennant, Brit. Zool. iv. p. 11, t. 40, f. 13, 1777. Brown, III. 

 Brit. Conch, t. 9, f. 11, 12. Catlow, Conch. Nomenc. p. 4. Dillwyn, 

 Desc. Cat. i. p. 38. Fleming, Edin. Encyc. vii. p. 100. Fleming, Brit. 

 Anim. p. 457. Forbes and Hanley, Brit. Moll. i. p. Ill, t. 2, f. 2 ; t. 4. 

 f. 1, 2 (Animal t. F. f. 3, 3a.) Hanley, Desc. Cat. p. 5, t. 2, f. 6. Jay, 

 Cat. 4th edil. p. 10. Montagu, Test. Biit. p. 22, t. 1, f. 7, 8. Philippi. 

 Neiier Conch, iii. Pholas, t. 2, f. 2. Sowerby, Illust. Brit. Conch, t. 1, 

 f. 10. Sowerby, Monog. Pholas, Thes. Conch, ii. p. 487, f; 31. 32. 

 Thorpe, Brit. Mar. Conch, p. 32, f. 71. Turton, Conch. Diet, p.143. 

 Turton, Conch, dith. Brit. p. 9. Wood, Gen. Conch, p. 82. Wood, 

 Index Test. t. 2, f. 6. 

 Barnia p arv a, Gray, Ann. and Mag. Nat. Hist. 2d ser. viii. p. 382. Gray. Figs. 



Moll. Anim. t. 338, f. 10. 

 Barnea p a r v a. H. and A. Adams, Genera, iii. t. 89, f. 3, 3a, b. Cbenu, Alan. ii. 

 f. 19. Fischer, Journ. Conch 2 ser. iii. p. 49. 

 Anchomasa Pennantiana, Leach, Moll. Gt. Britain, p. 253. 

 Pholas crenulatus, Solander. Spengler, Skrivt. Nat. ii. pt. 1, p. 92. 



" dactylus, var. Deshayes. In Lamarck Anim. sans Vert. vi. p. 45, note. 

 " dactyloides, Lamarck, Anim. sans Vert. v. p. 445. Menke, Syn. p. 73. 

 " Hgamentina, Deshayes, Traite Elem. p. 80, t. f. 11, 12i Catlow, Conch. 

 Nomenc. p. 4. 

 tuberculatus, Turton, Conch, dith. Brit. p. 5, t. 1, f. 7, 8. Brown, 

 Illust. Brit. Conch, p. 115, t. 49, f. 12, 13. Chenu, 111. Concbyl. t. 3, 

 f. 3. Fleming, Brit. Anim. p. 547. Hanley, Desc. Cat. p. 9. Thorpe, 

 Brit. Mar. Conch, p. 30. Wood, Index Test. Supp. t. 1, f. 3. 

 Sab. — England. 



Coll. Acad. Nat. Sciences. Coll. J. C. Jay, M. D. Coll. Isaac Lea, LL. D. 

 Coll. G. W. Tryon, Jr. 



Forbes and Hanley (Brit. Moll.), after an examination of the original speci- 

 men of Dr. Turtoii's Pholas tuberculatus, pronounced it to be a monstrosity of 

 B. p a r v a, and not a synonym of D. dactylus, as Gray and others sup- 

 posed. 



B. subtruncata, Sowerby. (Sp.) 



Pholas subtruncata, Sowerby, Zool. Proc. p. 69, 1834. Catlow, Conch. 

 Nomenc. p. 4. D'Orbigny, Moll. Voy. Amer. Merid. p. 499. Hanley, 

 Desc. Cat. p. 6. Jay, Cat. 4th edit. p. 10. Muller, Syn. Test. p. 236. 



Pholas lamdlosa, D'Orb. Voy. Am. Merid. p. 498, t. 77, f. 20, 21. 



Hob. — Payta, Peru, Isle Plata (subtruncata); Patagonia, south of Rio 

 Negro (lamelhsa.) 



Judging from the descriptions, D'Orbigny's species is founded on a variety 

 of subtruncata in which the anterior ribs are much more prominent. The 

 obtusely rounded form of the posterior end and the nearly parallel dorsal and 

 ventral margins distinguish this from B. par v a, to which, however, it is very 



