152 HELIX-ISOMERIA. 



H. TRIODONTA d'Orbigny. PI. 47, figs. 33, 34, 35. 



Orbicular-convex, carinate, umbilicate, thick, smooth, reddish- 

 brown ; spire short, obtuse ; whorls 5 ; aperture subrotund, pefistome 

 tridentate, whitish, brown inside; lip thick, reflexed. (Orbigny.) 



Umbilicate, conoid-semiglobose, solid, striatulate, chestnut-colored ; 

 spire conoid-convex, obtuse ; whorls 5*, slightly convex, the last 

 deflexed anteriorly ; periphery subacutely carinated, base malleated, 

 inflated around the umbilicus, constricted behind the peristome ; 

 aperture very oblique, broadly lunar ; peristome white, thick- 

 ened, reflexed, margins joined by an elevated callous, right margin 

 bidentate inside, basal margin provided with an obtuse tooth in the 

 middle. (Pfeiffer.') 



Alt. 21, diam. maj. 41, min. 35 mill. 



Guayaquil, Colombia. 



H. triodonta ORB. Voy. Amer. Merid., p. 234, t. 24, f. 1-3. PFR. 

 Monographia, i, p. 407, iv, p. 309. REEVE, Conch. Icon. f. 1473. 



H. JUNO Pfeiffer. PL 45, figs. 13, 14. 



I in perforate, or sometimes narrowly perforate, depressed, solid, 

 deep chestnut-colored, generally lighter around the axis beneath 

 and with a narrow lighter peripheral band ; surface shining, 

 obliquely substriate, very minutely, subobsoletely granulate, 

 obsoletely, more or less obviously obliquely corrugated above ; spire 

 short, obtuse ; whorls 4i, somewhat convex, separated by moderately 

 impressed sutures, gradually widening, the last whorl wider, slightly 

 oblong or dilated transversely, carinated at the periphery, the keel 

 becoming obsolete on the last third of the whorl, which is tumid 

 beneath, deflexed at the aperture, subconstricted behind the per- 

 istome ; aperture quite oblique, trapezoidal-lunar, bluish inside ; 

 peristome reflexed, thickened, flesh-colored, its face convex, termina- 

 tions connected by a callous ; upper and outer margins arcuate, 

 sometimes obsoletely dentate ; basal margin widened, with two very 

 blunt heavy teeth or folds near the coluraellar insertion, dilated 

 over or nearly over the umbilicus and appressed. 



Alt. 17, diam. maj. 32, min. 27 mill. 



Alt. 18, diam. maj. 35, min. 29 mill. 



Alt. 19, diam. maj. 33, min. 29 mill. 



Andes of Colombia, Ecuador and Peru. 



H. juno PFR. Zeitschr. f. Mai. 1850, p. 66; Raster's Conchyl, 

 Cab., p. 304, t. 127, f. 4, 5; Monographia, iii, p. 208. REEVE, 



