UROCOPTIS, S. G. GONGYLOSTOMA. 269 



convex; 17.5 to 21x2 mm., with 17-25% whorls 

 in truncate shells. U. ischna, no. 154. 



4. Smooth, often faintly tessellate with opaque white; 

 whorls but slightly convex ; 13-15 x 1.7-2 mm., with 

 19-24 whorls in entire shells. U. porrecta, no. 155. 

 II. Smaller, 12 x 3 mm. ; brown with a red-gold gleam, and 

 snow-white, straight ribs ; whorls 13 in entire, 10 in trun- 

 cate shells. U. blainiana, no. 166. 

 III. Small, length 14 mm. or less, not sculptured like II. 



1. Smooth or nearly so. 



a. Smooth, glossy, corneous marbled with white, 

 aperture brown inside ; 10-11 x 1.6 mm., whorls 

 16-18. U. sexdecimalis, no. 157. 



6. Similar, blue- white streaked with corneous; 

 11 x nearly 2 mm., whorls 16. 



U. clerchi, no. 158. 



c. Corneous with some white lines and spots; 

 irregular, narrow, thread-like riblets ; 12 x 1.6 

 to 2 mm., whorls 20. U. camoensis, no. 159. 



d. Opaque fleshy-white, with wedge-shaped cor- 

 neous-brown stripes ; glossy and smooth ; 9.5 x 

 1.7 to 2 mm., 13y 2 to 14 whorls. 



U. marmorata, no. 160. 



2. Shell ribbed. 



a. Subarcuately costulate, ashen with chestnut 

 aperture ; whorls flattened ; 14 x 2.6 mm., trun- 

 cate with 12 whorls. U. cinerea, no. 156. 



b. Corneous with some white lines and spots; 

 irregular thread-like riblets ; 12 x 1.6 to 2 mm., 

 with 20 whorls. U. camoensis, no. 159. 



c. Fusiform, swollen in the middle; flesh- tinted 

 with some pale brown markings; delicately 

 costulate ; 9.5 x 1.6 mm., whorls 14, entire. 



U. rugeli, no. 161. 



d. Similar but stronger ribbed ; 9.5 x 2 mm., with 

 11 whorls, truncate U. r. euglypta, no. 161a. 



e. Obliquely sharply striate; corneous- whitish 

 obsoletely variegated with brownish ; 12.5 x 2.6 



