246 UROCOPTIS, S. G. GONGYLOSTOMA. 



Group of U. coerulans. 



Shell moderately stout, truncate, variegated with white on 

 a corneous or brown ground, the aperture usually brownish 

 within, basal keel obsolete; axis with one or two spiral 

 lamellae, the lower denticulate, at least above ; a row of whit- 

 ish subsutural beads developed. Western Cuba. 



Key to Species. 



I. Axis encircled by a single, sub-basal lamella. 



1. Length 20 to 21, diam. 4.5 to 5.5 mm.; whorls 

 11-12 ; solid, brown and white, regularly rib-striate ; 

 axis weakly spiral above the lamella. 



U. coerulans, no. 135. 



2. Length 14 to 15.5 x 4.3 to 4.6 mm. ; whorls 8 to 9 ; 

 otherwise like U. coerulans. U. c. incerta, no. 135a. 



3. Length 13 to 15, diam. 3.3 to 4 mm. ; whorls 10y 2 

 to Iiy 2 ; corneous variegated with cream- white ; 



whitish spaced riblets. U. discors, no. 130. 



4. Length 11 to 14, diam. 2.5 mm. ; like variegata, but 

 with more remote riblets. V. canteroiana, no. 136. 



5. Length 9.5 to 11, diam. 2.5 to 3 mm.; whorls 7y 2 

 to 8!/2 ; riblets few and irregular, suture with 

 curved, hook-like nodes ; axis somewhat spiral above 

 the lamella. U. unguiculata, no. 129. 



6. Length 9 to 10.3, diam. 2.2 to 2.3 mm.; whorls 8 

 to 9!/2 ; brownish with white streaks and some white 

 sutural nodes, nearly smooth or sparsely ribbed. 



U. gonzalezi, no. 127. 



7. Length 11 to 12, diam. 2.5 to 2.7 mm. ; brown, some- 

 times variegated with white, and having regular, 

 white sutural beads; the surface closely striate. 



U. joaquini, no. 128. 



II. Axis with two subequal lamellce above the middle of the 

 shell, one in the lower whorls, the axis often weakly 

 spiral above it. 



1. Shell finely striate, with small, regular subsutural 

 beads; length 12 to 15, diam. 3 to 3.2 mm.; whorls 

 9 to 10y 2 . U. afflnis, no. 132. 



