214 UROCOPTIS, S. G. GONGYLOSTOMA. 



&. Finely striate; whorls 14-15, 11-12x2.5 mm. 



U. fraterna, no. 101, 

 c. Striate; whorls 10-11. 



aa. Striation coarse and low or subobso- 

 lete; upper lamella obsolete in upper 

 half of shell; 10-12x3-3.3 mm. 



II. distincta, no. 98, 



&&. Opaque, carinate below ; 10 x 2.75 mm. 

 U. consanguinea, no. 99, 

 cc. Smooth on convexity of whorls, else- 

 where regularly striate; 10-12x2.3-2.7 

 mm. U. cristallina, no. 100, 



dd. Densely hair-striate ; 15x3.3 mm.; like 

 U. fortis in shape and sculpture. 



U. fumosa, no. 102, 

 2. Spire entire, not truncate. 



a. Ribbed; 15.5x3 mm.; whorls 141/2. 



U. fusiformis, no. 104, 



&. With wide-spaced, thread-like striae, stronger 

 near the sutures; 13-16 x 2.6 to 3 mm. ; whorls 

 15 to 17. U. integra, no. 105, 



c. Finely striate; neck descending; 13 to 17 

 x2.5 mm., whorls 17-19. 



U. angustior, no. 103. 



d. Closely, obsoletely striate, whitish; 16x2.25 

 mm., whorls 17. U. imparata, no. 106, 



IV. Small, slender species, with a single spiral axial thread 

 or lamella (group of U. capillacea). 



1. Sculpture of wide-spaced thread-like riblets. 



U. remota, no. 109; U. garciana, no. 108; Z7. 

 fusiformis, no. 104; U. crassildbris, no. 114 



2. Closely striate or nearly smooth. 



a. Apex entire; very closely and very finely 

 striate; 10 to 12x2.5 mm., whorls 13-14. 



U. capillacea, no. 112. 



&. Truncate; like U. elegans, but axis encircled 

 by a thick thread. U. moralesi, no. 110. 



