70 HELICEA. 



HELIX PROFUNDA SAY vol. ii. p. 177, pi. xxii. 



Helix prof undo, SAY, (Binney's ed.) pp. 20, 36, pi. 37, fig. 3. 



DEKAY, N. Y. Moll. p. 42, pi. iii. fig. 38. 



CHEMNITZ, ed. 2, ii. p. 63. 



PFEIFFER, 1. c. iii. 265. 



CHENU, Bibl. Conch, iii. 51, pi. xiii. fig. 26. 



DKSHAYES in Fer. i. 69. 



REEVE, Con. Icon. No. 682, (1852). 



MRS. GRAY, Fig. Moll. An. pi. cxciii. fig. 12. (Ex. Bost. Journ.) 

 Helix Ricliardi DESHAYES in Lam. 3d ed. iii. 283. 



CHENU, 111. Con. xii. 13. 



DELESSERT, Rec. des Coq. pi. xxvi. fig. 7. 

 Polygyra profundum ADAMS, Gen. Rec. Moll. ii. 207, (absq. desc.)? 



The shell figured in Ferussac, pi. 69 G, figs. 9, 11, and 

 referred to as var. /? by Pfeiffer, is merely one of the many 

 varieties of the species. 



I have a specimen collected by Mr. T. A. Conrad on 

 Broad Top Mountain, Pennsylvania. It occurs fossil in 

 the Postpleiocene. 



HELIX SAYII BIKNEY vol. ii. p. 180, pi. xxiii. 



Helix Sayii, CHEMNITZ, ed. 2, No. 976, tab. cxlviii. figs. 13, 14. 



MRS. GRAY, Fig. Moll. An. pi. 193, fig. 10. (Ex. Bost. Journ.) 



DESHAYES in Fer. i. p. 79. 



REEVE, Con. Icon. No. 679, (1852). 



Helix diodonta SAY, (Binney's ed.) p. 39, pi. Ixxiv. fig. 4. 

 DEKAY, N. Y. Moll. p. 34, pi. ii. fig. 18. 



Thave it also from Pennsylvania. 



HELIX TRIDENT AT A SAY vol. ii. p. 183, pi. xxvii, 



Helix tridentata SAY, (Binney's ed.) p. 6, pi. Ixx. fig. 1. 



DEKAY, N. Y. Moll. p. 28. pi. ii. fig. 7. 



POTIEZ et MIOHAUU, Gal. p. 114. 



MRS. GRAY, Fig. Moll. An. pi. 291, fig. 3. (Ex. Bost. Journ.) 



CHEMNITZ, 1. c. i. 84. 



PFEIFFER, 1. c. iii. 263. 



DESHAYES in Lam. ed. 3, iii. 309, in Fer. 1. c. i. 72. 



REEVE, Con. Icon. No. 690, (1852). 

 Tnodopsis lunula RAFINESQUE, En. and Ace. p. 3. 



I propose to separate from tridentata Binney both fallax 

 and Hopetonensis. Their distinctive characters are suf- 



