21 



— spire convex, interiorly riither convex, umbilicus 



distinct in young, obsolete in older examples; 

 whorls 6, finely striated above, shining all over, 

 color pale horn; diam. 7, alt. 4 mill, suppressus, Say. 



5 umbilicus wide, perspective; spire depressed-conic, 



diam. 5.5, alt. 2.3 mill., surface with fine, regular 

 rib-striae; whitish colorless; whorls 4^. 



limatulus. Ward. 



— not so. 6 



6 diam. 11 mill, or more; sh. yellowish horn colored, 



somewhat opaque, with a white testaceous deposit 

 in the last whorl near the aperture; umbilicus 

 quite narrow. 7 



— diam. 5 to 8 mill.;sh. greenish to brownish horn col- 



ored, transparent; umbilicus rather wide. 9 



7 diam. 15, alt. 10 mill., or somewhat less. 8 



— diam. 11 to 12, alt. 6 mill.; surface with fine strict, 



shining; suture impressed; whorls 6. demissus, Binn. 



8 irregularly striated above, rather smooth below, 



shining, whorls 7. , ligerus, Say. 



— finely and regularly striated all over, with fine re- 



volving lines; last whorl with a light band at the 

 periphery, and usually a brown one above it. 



intertexus, Binn. 



9 diam. 7 to 8, ak. 3.7 mill.; whorls 5 to <,}i, rather well 



rounded, suture deep; color deep brownish or 

 greenish horn. (Eu.) nitidus, Mull. 



— diam. about 5, alt. 2.8 mill; somewhat depressed, 



and so the 4 to 5 whorls; suture rather deep; color 

 light reddish or brownish horn, sometimes light 

 greenish horn; surface finely irregularly striated, 



arboreus, Say. 



