192 UROCOPTIS, S. G. GONGYLOSTOMA. 



Urocoptis with 3 to 8 spiral axial lamellae, increasing in 

 size from the upper to the lower, which is largest, and more 

 or less crenate at the edge in the upper whorls. Last whorl 

 shortly free, not descending, rounded beneath, the basal keel 

 a low cord or obsolete. Sculpture of fine striae. Spire shortly 

 truncate, the abandoned portion of few (about 6-7) whorls, 

 and not attenuate near the smooth apex. 



A group of western Cuba, east to Matanzas, differentiated 

 from typical Gongylostoma by the multiplication of axial 

 lamellae, the non-attenuate, short abandoned portion of the 

 spire, and the larger size. 



Key to Pycnoptychia, etc. 



I. Surface finely and closely striate. 



1. Shell sinistral, very finely and closely striate. 



U. scava, no. 64. 



2. Shell dextral. 



a. Axial lamellae more than 3; diam. of shell 

 one-fourth the length or less. 



&. Striae close and fine, as wide as the in- 

 tervals. U. humboldtiana, no. 61. 

 &6. Striae more spaced, the intervals wider. 



U. h. peraffinis. 



aa. Three axial lamellae; diam. more than one- 

 fourth the length ; very densely striate, glossy. 



U. striatella, no. 63. 

 II. Surface dull, sculptured with spaced rib-striae. 



1. Interior the color of the outside ; shell but slightly 

 tapering above, thin. U. shuttleworthiana, no. 65. 



2. Opaque; interior brownish or dark; sculpture of 

 light riblets on a dark ground. 



Group of U. trilamellata, no. 139, etc. 



U. torrei (no. 62), an insufficiently described species, is also 

 provisionally included in this section; also U. oviedoiana, no. 

 66, the interior of which is unknown. 



61. U. HUMBOLDTIANA (Pfeiffcr). PL 47, figs. 77-81. 



Shell cylindric, the upper third tapering to a rather wide 



