HELIX-CARACOLUS. 121 



H. excellens PFR.. Zeitschr. f. Mai. 1852, p. 133 ; Conchyl. Cab. t. 

 161, f. 12 ; Monographia iii, p. 166. 



May be separated from H. carocolla by the narrow triangular 

 aperture, concave spire, smoother surface, etc. See analysis of species 

 on page 119. 



H. INSITITIA Shuttleworth. PL 21, figs 3, 4 ; pi. 24, figs. 35-,- 



Imperforate, depressed-conoiclal, solid, shining, dark brownish- 

 olive, sutures margined with yellow, inner whorls brown or reddish ; 

 surface striatulate, about as smooth as in H. excellens. Spire conical, 

 outlines nearly straight ; apex depressed, subplanulate ; sutures lin- 

 ear ; whorls 5, slightly convex, the outer ones wider than in H. 

 carocolla; body-whorl acutely carinated, depressed, a trifle descend- 

 ing anteriorly, flattened beneath, and a little indented in the center 

 around the axis, but less so than H. carocolla ; aperture very oblique, 

 subtriangular, livid within ; peristome white or livid-brown ; upper 

 margin blunt, curved (not straight as it is in H. excellens), basal 

 margin slightly expanded, thickened ; terminations of peristome 

 joined by a rather heavy whitish callus, which under a strong lens 

 seems to be smooth or nearly so. Alt. 24, diam. 47-50 mill. 



Hayti. 



H. insititia SHUTT. Diagn. no. 6, p. 133. PFK. Monogr. v, p. 

 262. H. carocolla var. PFR. Monogr. iii, p. 166. H. carocolla 

 REEVE, Couch. Icon. f. 227. 



Distinguished by the decidedly olive-green color, smooth parietal 

 callus, margined sutures and rapidly widening whorls. Some spec- 

 imens are more brown than green, and the yellow subsutural margin 

 is sometimes not very prominent. See under H. carocolla. The 

 species is often more depressed than either of my figures. 



H. SARCOCHEILA Morch. PL 56, figs. 1, 2. 



Imperforate, depressed-conical, solid, somewhat shining, dull 

 chestnut-brown, sometimes a trifle tinged with olive, obliquely 

 striate like H. carocolla, and with microscopic decussating scratches ; 

 spire rather straightly conical, apex rounded, depressed, subplan- 

 ulate ; sutures linear ; whorls 6$ to 6, a little convex, the last rather 

 wide, depressed, acutely carinated, not descending anteriorly, scarcely 

 indented around the axis ; aperture quite oblique, trigonal-lunate, 

 livid-white within ; peristome white or slightly flesh-tinted, upper 

 margin obtuse, slightly curved, basal margin expanded, thickened, 



