223 



Costse lamellose, near together, 6. >S'. foliosa. 



Costfe filiform, varices prominent ; fenestrated ; whorls 



almost disjointed. 7. >S'. orycta. 



5. Shell costated and variced, j)unctate ; basal keel ending at 



inner angle or middle position of aperture [Punctiscala]. 

 Whorls medially angulated ; shell turrited ; spirally finely- 

 lirate. S. S. loxojileura. 



Whorls not angulated. 



Shell elongate-turrited. 



Whorls convex, spirally lirate. 



9. S. hulbulifera. 



Whorls flattish, spirally linear-sulcate. 



10. S. eritima. 

 Shell pyrimidal ; whorls slightly convex, spirally 



wavy-striated, costas dentate at posterior suture. 



11. S. microrhysa. 



6. Shell costated and variced, impunctate ; basal keel ending 



at outer angle of aperture [Cirsotrema]. 

 Costse filiform ; coarsely lirate, subgranose at intersections. 



12. S. transenna. 

 Costse lamellose ; spirally lirate and striated. 



Lamellae lamellose, straight-edged. 



13. >S'. JIariae. 

 Lamellae crowded, frilled. 14. a!?. pleiojjhyUa. 



IIL Peristome incomplete. 



7. Periphery angulated, aperture subquadrate, columella flat- 



tened and angulated in front, base lirate ; shell thick, 

 tessellated, without varices [Eglisia]. 



15. S. trijjlicata. 



8. Periphery angulated, aperture oval ; shell thin, cancellated, 



with or without varices [Acrilla]. 

 Base disk-like. 



Shell smooth, minutely umbilicated. 



16. S. inornata. 

 Shell costated, imperfectly variced. 



17. S. j^achypleura. 

 Base subangulated and lirate. 



Costa? filiform and distant. 

 Whorls convex. 



Tessellated by equal lira? and costae. 



18. S. escharioides. 

 Costse stout, lirae slender ; apical whorls 



angulated. 19. aS'. glyphospira. 



Costse thick ; spirally linear-sulcate ; apical 



whorls bulbiform. 20. S. mutica. 



