186 UROCOPTIS, S. G. GONGYLOSTOMA. 



white with corneous stripes; extremely 

 slender, generally with a long descend- 

 ing neck; axis with a single small la- 

 mella. Central and eastern Cuba. 



Group of U. wrighti, no. 146-151. 



6. Axis with one or two weak spirals, not denticulate 

 or spinose ; shell very slender with round neck. 



Section Tetrentodon, no. 152-166. 



Section Fibricutis Pilsbry, 1903. 



Small, cylindric and truncate, roughly striate, and crenate- 

 at the sutures, with a spinose axial lamella; the rejected 

 whorls numerous, forming a slender, attenuate spire; 2% 

 nepionic whorls vertically costulate. (Fibra, filament; cutis r 

 skin.) 



By the structure of the axis, the single species of this group 

 would belong to Gongylostoma (in the wide sense) ; but by 

 the external sculpture, and especially that of the nepionic 

 shell, it approaches Idiostemma. The relationships of the 

 group must be considered uncertain until the dentition is 

 examined. It occurs in Santiago province, the Idiostemma 

 country. 



56. U. SCABROSA ('Gundl.' Pfr.). PL 58, figs. 69, 70. 71. 



Shell small, cylindric-tapering, lustreless, pale fleshy, 

 densely sculptured with fine, interlacing white stria, forming 

 an irregular fibrous or netted pattern; with low white bosses 

 below the suture, and sometimes above it also. Spire slowly 

 tapering, rather widely truncate ; whorls convex, the last very 

 shortly free. Aperture circular, the lip slightly expanded. 

 Axis encircled by a small lower lamella, which is densely and 

 delicately spinose, and a low, slightly spiral cord above it, 

 both disappearing in the earlier whorls. About 11 early 

 whorls are cast off, this portion being subulate, attenuated 

 towards the noticeably bulbous apex, the nepionic shell con- 

 sisting of 2% vertically costellate whorls. 



Length 9.5, diam. 2.5 mm. ; whorls 9-10. 



Eastern Cuba: Yateras, under stones (Gundlach) ; Pal- 

 enque, dist. of Alto Songo, prov. Santiago (Wright). 



