61 



Synonymy of the Species of STREPOMATID^, a Family of Fluviatile MoUusca 



inhabiting North America. 



Part 3. 



BY GEORGE W. TRYON, JR. 



Genus SCHIZOSTOMA, Lea. 



Sc/uzoatoma, Lea, Philo3. Proc. ii. p. 242, Dec. 1842, iv. p. 16Y, Aug. 1815. 



Philos. Trans. X. p. 67,1847. Obs. iv. p. 41,1847. Proc. Acad.- Nat. 



Sci., May, 18(30. Jour. Acad. Nat. Sci. v. pt. 3, p. 245, Mar., 1863. Obs. 



ix. p. 67. 

 Schizocheilus, Lea, Philos. Trans, x. p. 295, 1853. Obs. v. p. 51, 1853. 

 Gyrotoma, Shuttleworth, Mitthcil, Naturforsch. Bern. p. 88, July 22, 1845. 



Adams, Genera, i. p. 305, Feb., 1854. Gray, Guide to Mollusca, i. p. 103, 



1857. Chenu, Man. de Conciiyl. i. p. 293, 1859. Anthony, Proc. Acad. 



Nat. Sci., p. 63, Feb., 1860. Binney, Check List, June, 1860. Brot, 



List, p. 27, 1862. 

 Melatoma, Anthony, Gray, Zool. Proc, p. 153, 1847. Woodward, Manual, p. 



131, 1851. Reeve, Conch. Icon., Mar., 1860. 

 Apella, Mighels, MSS. 



SYNOPTICAL TABLE OF SPECIES.* 



Fismre direct, narroio, and deep. Fissure oblique, short, and icide. 



1. Shell striate or ridged. 



a. Shell conical, spire lengthened, sharply carinate. 



1. S. Cariniferum, Anthony. 15. S. p a g o d u m. Lea. 



S. Showalterii, Lea. 16. S. p y r a m i d a t u m, Shutt. 



2. S. cast an e urn. Lea. 17. S. W e t u m p k a e n s e. Lea. 



S. ornala, Anth. 



S. pagoda, Lea, of Reeve. 



b. She'l conic-cylindrical ; spire obtuse, not carinate. 



3. S. V i d e u m, Shuttleworth. 18. S. Alab £im e n s e, Lea. 



19 S. Anth ny i, Lea. 



4. S. e X c i s u m, Lea. 20. S. b a b y 1 o n i c u m, Lea. 



, S])illmanii, Lea. 



c. Shell globosely-ovate, spire moderate. 



5. S. p u m i 1 u m. Lea. 21. S. B u d d i i, Lea. 



Globosum, Lea. S. funiculatum. Lea. 



Alabamense, Lea, of Reeve. /S. pagodum, Lea, of Reeve. 



Showalterii, Lea, of Reeve. 



2. Shell smooth, 

 d. SI' ell elliptic. 



6. S. e 1 1 i p t i c u m, Anthony. 



7. S. 1 a c i n i a t u m, Lea. 



e. Shell quadrately cylindrical. 



8. S. a m p 1 n m, Anthony. 22. S. d e m i s s u m, Anth. 



9. S. nnculum, Anthony. S. Hartmanii, Lea. 



23. S. CO n str ic tum. Lea. 

 S. rectum, Anth. 



* The Schizodnmie contain iwo nearly equal groups, characterized respectively by a narrow 

 direct, and an nblique, Hliort, wiile s^lit. 



In the above tiible the opposite speries in the two groups are generally exactly similar except 

 in the character of the slitl 



