214 UROCOPTIS, S. G. GONGYLOSTOMA. 



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



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. 



U. distincta, no. 98. 



6&. Opaque, carinate below; 10x2.75 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 ; 15 x 3.3 mm. ; like 

 U. fortis in shape and sculpture. 



U. fumosa, no. 102. 

 2. Spire entire, not truncate. 



a. Ribbed ; 15.5 x 3 mm. ; whorls 14%. 



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 ; 16 x 2.25 

 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 ; U. 

 fusiformis, no. 104; U. crassilabris, 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. 



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

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



