61 



Synonymy of the Species of STREPOMATID.E, a Family of Flnviatile Kollnaca 

 inhabiting North America. 



Part 3. 



BY GEORGE \V. TRYON, JR. 

 Genus SCHIZOSTOMA, Lea. 



Sihizostoma, Lea, Philos. Proc. ii. p. 242, Dec. 1842, iv. p. 167, Aug. 1845. 



Philos. Trans, x. p. 67,1847.. Obs. iv. p. 41, 1847. Proc. Acad. :N r at 



Sci., May, 1860. 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, Mittheil, 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 Conchy!, 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. 



SYNOPTICL TABLE OF SPECIES.* 



Fissure direct, narrow, and deep. Fissure oblique, short, and wide. 



1. Shell striate or ridged, 

 a. Shell conical, spire lengthened, sharply carinate. 



1. S. Carin if er u m, Anthony. 15. S. p a g o d u m, Lea. 



S. Showalterii, Lea. 16. S. pyramidatum, Shutt. 



2. S. castaneum, Lea. 17. S. W* e t u m p k a e n s e, Lea. 



S. ornafa, Anth. 



S. pagoda, Lea, of Reeve. 



b. Shell conic-cylindrical ; spire obtuse, not carinate. 



3. S. o v o i d e u m, Shnttleworth. 18. S. Al ab am e nse, Lea. 



19 S. Antho 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. 



Spillmanii, 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. 



Globoswn, Lea. S. funiculatum, Lea. 



Alabamensc, Lea, of Reeve, S. pagodum, Lea, of Reeve. 



Showalterii, Lea, of Reeve. 



2. Shell smooth, 

 d. S'- 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. amp lu m, Anthony. 22. S. dem iss um, Anth. 



9. S. n u c u 1 u m, Anthony. S. ffarlmann, Lea. 



23. S. cons trie turn, Lea. 

 S. rectum, Anth. 



*The SchizosbimsR contain two nearly equal groups, characterized respectively by a narrow 

 direct, and an ublique, short. wi.Je flit. 



In the above table the opposite species in the two groups are generally exactly siirilir except 

 in the character of th slit! 



