UROCOPTIS OF JAMAICA. 133 



being a little contracted just below the smooth apex, and more 

 so just before the beginning of the permanent whorls. Fig. 

 1 of pi. 64 is from a specimen in coll. of G. H. Clapp, retaining 

 all but the first whorl ; loc., interior Clarendon. 



13. U. DUBIA (Chitty). PL 29, figs. 18, 19, 20. 



"Of the C. rosea group. Shell ovate-conic, much elon- 

 gated, dingy rose color; lip white; moderately coarse oblique 

 stria of growth; keel nearly obsolete; last whorl very much 

 rounded, and brownish; spire with convex outlines; apex 

 truncate, with the loss of whorls; 7% whorls left, very 

 convex and rather shouldered, with a deeply impressed suture ; 

 last whorl moderately produced, subangular on the right side 

 and at the upper part of the left. Aperture large. Lip 

 spreading much on the left lower extremity, thin shining and 

 slightly reflected. Length .67, breadth .17, breadth of lip .17 

 inch." (Chitty). 



Jamaica : Parish of St. James, near Maroon Town ( Chitty, 

 Jarvis), and at Montpelier (Henderson); Mackfield, West- 

 moreland (Jarvis). 



Cylindrella dubia CHITTY, Contrib. to Conch., no. 1, p. 13 

 (October, 1853). PFR., Monogr., iv, p. 697. 



Distinct from ambigua by its smaller size and especially 

 the more slender form. Specimens from Maroon Town and 

 Hanna Rock, five miles distant (pi. 29, figs. 18, 19), vary 

 widely in size : 



Length 16.5, diam. 4.3 mm. ; whorls 7%. 



Length 15, diam. 5.5 mm. ; whorls 6%. 



Length 21.3, diam. 5.6 mm. ; whorls S l / 2 . 



Length 20, diam. 6.2 mm. ; whorls 7%. 



The mouth is almost circular, the upper margin of the lip 

 being more arcuate than is usual in U. ambigua. The whorls 

 vary a great deal in convexity, but are often more convex 

 than in U. ambigua. The basal keel is weak or almost want- 

 ing, and in the form from around Maroon Town it is not 

 strengthened just behind the lip, as it generally is in ambigua. 



A large series collected by Henderson and Simpson at Mont- 

 pelier, on the western border of St. James, is less variable in 



