122 



UROCOPTIS OF JAMAICA. 



3. Group of U. nobilior. Turrite, tapering large species. 



They live on the ground among leaves, etc. U. ndbilior 

 occurs at Bogwalk in a talus of decomposed shaly rock, of 

 which the shells are almost exactly the color. 



The wide range of variation and the intergradation of geo- 

 graphically adjacent races, renders the definition of species 

 exceedingly difficult. Clear definitions and easy "keys" can- 

 not be expected where no sharp distinctions exist in nature. 

 There has been a good deal of differentiation, so that in the 

 areas where the divergence of the various forms is most accen- 

 tuated, they seem to be fairly distinct as species go ; but else- 

 where a multitude of less divergent local forms occur, more 

 or less uniting the several main races. 



(Group of U. brevis.) 

 6. U. BREVIS (Pfeiffer). PL 33, figs. 96-99, 1-3, 10-12; pi. 32, 



figs. 76, 84, 86. 



"Shell rimate, truncate, cylindric-ovate, the apex rounded, 

 obtuse ; very closely, obliquely rib-striate ; pale brown, a little 

 glossy. Whorls 7, flattened, the later ones subequal, the last 

 whorl shortly free, the base usually very obsoletely carinate. 

 Aperture circular; peristome broadly expanded and a little 

 reflexed. Length 16%, diam. 7 mm. ; diam. of aperture 5 

 mm." (Pfr.) 



Jamaica : Widely distributed along the south coast, from 

 St. Thomas to St. Elizabeth, and inland 6 or 7 miles, but not 

 above 500 ft. elevation (Jarvis). Area 3 of map no. 2. 



Helix brevis Fer. in Mus., according to Pfr. Cylindrella 

 brevis PFR., Symbols, i, p. 47 (1841) ; in Philippi, Abbild., i, 

 p. 185, pi. 1, f. 1; ii, p. 49, pi. 2, f. 18; Monogr., ii, p. 371; 

 Conchyl. Cab., pi. 2, f. 10-17. ORB., Moll. Cuba, i, p. 182, pi. 

 12, f. 12-14. DESK, in Fer., Hist., ii, p. 226, pi. 164, f. 10-12. 

 CROSSE & FISCHER, Journ. de Conchyl., 1870, p. 9, 12, pi. 3, 

 f. 6 (jaw), pi. 5, f. 14. GLOYNE, J. de C., 1872, p. 34. 

 BLAND, Amer. Journ. of Conch., iv, p. 186 (jaw). JOHNSON 

 & Fox, Nautilus, v, p. 34. RUSH, Nautilus, v, p. 69, no. 118. 

 HENDERSON, Nautilus, viii, p. 19, no. 86 (except loc. Ocho 

 . yClausilia torticollis CROUCH, Illustr. Introd. to La- 



