HELIX THELIDOMUS. 63 



not nearly so great as in H. bayamensis, trinitaria, rangelina, bar- 

 racoensis, proboscidea, guatanemensis, or even provisoria. The body- 

 whorl is more globose than that of rangelina, and the columellar 

 plate is not, usually decidedly truncate as in that species. 



Var NOSCIBILIS Fer. PI. 3, fig. 31 ; pi. 1, figs. 7, 8, 9. 



Shell similar to the type in form ; straw-colored ; whorls 4, callus 

 plate of the columella slightly subtruncate at base or nearly straight. 



Alt. 16, diam. maj. 20, min. 18 mill. 

 This form leads toward H. emarginata. 



Var. ZETA Pfr. PL 3, figs. 24, 25. 



Solid, globose-conoid, basal margin of the peristome strongly den- 

 tate. This may be a form of H. rangelina, which it resembles exact- 

 ly in the columella. Although many specimens are before me I am 

 unable to satisfy myself regarding it. 



Var. PROVISORTA Pfeiffer. PL 17, figs. 41, 48, 49. 



Imperforate, globose-subdepressed, moderately solid or thin, yellow- 

 ish russet colored costulate-striate above, the costulse strong, pretty 

 regular, smooth, bifurcating but rarely, base smooth, glossy ; spire 

 short, low-con.oid.al, apex obtuse, first 1J whorls smooth, whitish, 

 glossy; sutures moderately impressed; whorls 3 2 to 4, moderately 

 convex, rapidly increasing, the last slightly dilated transversely, 

 rounded, tumid below, deflected anteriorly; aperture oblong-truncate, 

 oblique ; peristome slightly expanded or not perceptibly so, some- 

 what thickened, but less so than in the allied species, upper and out- 

 er margins arcuate, baso-columellar margin flattened, its inner edge 

 thin, straight or concave, not truncate below, somew r hat angled 

 where it joins the outer lip or rounded there. 



Alt. 20, diam. maj., 27, min. 22 J mill. 



Baracoa etc., Eastern Cuba; New Providence, Bahamas. 



H. provisoria PFR.. Malak. j5/. 1858, p. 39. and Monogr., v, p. 288. 

 -ARANGO, Fauna Mai. Cubana, p: 72. (H. appendiculata GUNDL., 

 in sched., 1859.) 



Like H. bayamensis, this shell is coarsely costulate above, glabrous 

 beneath. From that species it maybe distinguished by the general- 

 ly smaller size, more inflated, less depressed body-whorl and the 

 (usually) less developed peristome. It is also less dilated transversely 

 than bayamensis. From H. auricoma it may be separated by its 

 slightly more transversely-dilated form. But there seems to be no 



