352 LAND AND FRESH-WATER SHELLS OF N. A. [pART IV. 



SYNOPTICAL TABLE OF SPECIES.* 



FISSITRE DIRECT, NARROW AND DEEP. FISSURE OBLIQUE, SHORT AND WIDE. 



I. Shell striate or ridged. 



A. Shell conical, spire lengthened, sharply carinate. 



1. S. CAKiNiFERUM, Aiithony. 15. S. pagodum. Lea. 



*S'. Showalterii, Lea. 16. S. pyuamidatum, Shutt. 



2 S. CASTANEU5I, Lea. 17. S. Wetumpkaexse, Lea. 



S. ornata, Anthonj\ 

 S. pagoda. Lea, of Reeve. 



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



3. S. OA^oiDEUM, Shuttleworth. 18. S. Alaijamense, Lea. 



19. S. Anthoxyi, Lea. 



4. S. ExcisuM, Lea. 20. S. Babylonicum, Lea. 



Spillmanii, Lea. 



C. Shell globosely-ovate, spire moderate. 



5. S. PUMILUM, Lea. 21. S. Buddii, Lea. 



Globosum, Lea. S. funiculatum, Lea. 



Alabamense, Lea, of Reeve. S. imgodum. Lea, of Reeve. 



Showalterii, Lea, of Reeve. 



2. Shell smooth. 

 D. Shell elliptic. 



6. S. ELLIPTICUM, Anthony. 



7. S. laciniatum. Lea. 



E. Shell quadrately cylindrical. 



8. S. AMPLUM, Anthony. 22. S. DEMissiiM, Anthony. 

 !). S. NUCULUM, Anthony. 8. Ilartmanii, Lea. 



23. S. constrictum. Lea. 



8. rectum, Anthony. 

 23a. S. SiiowALTERiANA, Lea. 

 10. S. cylindraceum, Mighels. 24, S. salebrosum, Anthony. 



S. robustum, Anthony. 



8. rectum, Anth., of Reeve. 



• In tlie above table tbe opposite species in tlic two groups are generally exactly simi- 

 lar except in the cliaracler of the elit. 



