HELIX-CARACOLUS. 127 



when present are well defined, not shading into the ground-color as 

 in var. marginelloides. 



Var. BORNII Pfr. PI. 55, figs. 6-9. 



Umbilicus rather broad and deep ; form depressed ; acutely 

 carinated ; last whorl moderately defiexed anteriorly ; surface 

 obliquely striate ; color yellowish, with one deep brown zone above 

 and one below the carina, the zones sometimes very wide, almost 

 covering the whole surface. Aperture trigonal-oval, transverse, not 

 conspicuously angled at the position of peristome ; peristome ex- 

 panded, somewhat thickened, convex, white, not adnate over the 

 umbilicus. Alt. 16, diam. 37 mill. 



Porto Rico ; Vieque. 



Var. BIZONALIS Desh. PL 22, figs. 18, 19. 



Umbilicate, depressed, obtusely angled at the periphery ; obliquely 

 striate ; yellowish, with two deep brown zones, one above, one 

 beneath; outlines of spire convex; last whorl slightly deflexed an- 

 teriorly ; aperture subhorizontal, transverse-oval, not angled at 

 position of periphery ; expansion of columellar lip partly covering 

 the umbilicus. Alt. 14-15, diam. 29-32 mill. 



Hayti. 



Separated from other varities by the almost rounded periphery. 

 Not a common species- I have not traced the forms uniting this 

 with the acutely carinated types. It is therefore more distinct than 

 the other forms. 



Var. GASKOINI Pfr. PL 22, fig. 11. 



Umbilicate, turbinate-depressed, solid obliquely rugose-plicate, 

 above; shining, white; spire conoid, obtuse; whorls 5, convex, the 

 last deflexed anteriorly, carinated ; base slightly convex, nearly 

 smooth ; aperture very oblique, lanceolate-oval, peristome narrowly 

 expanded, somewhat thickened, the terminations converging, joined 

 by a white callus ; basal margin reflexed, half covering the narrow 

 umbilicus. Alt. 15-17, diam. 30-31 mill. 



Hayti. 



May be known by the conoidal form, strong incremental folds of 

 the upper surface, absence of color, etc. It is doubtless, as Bland 

 supposed, a form of H. bizonalis, and connects that variety with the 

 more sharply carinated forms of Caracolus marginella. 



