HELIX-ISOMERIA. 137 



H. procera PFEIFFER, Proc. Zool. Soc. Lond. 1853, p. 127; Mon- 

 ographia iv, p. 308. REEVE, Conch. Icon., f. 1273. 



There is a variety w r ith thin somewhat fugacious straw colored or 

 buff cuticle, of which a specimen received from BLAND is before me. 



The species may be known by its large umbilicus, quadrate aper- 

 ture with subparallel upper and lower margins, the upper somewhat 

 arcuate, the lower nearly straight. The aperture is nearly as high 

 as wide. The form is generally intermediate between that of figures 

 12 and 18 ; it is rarely so elevated as the former. 



The H. procera Pfr. seems to me to be completely synonymous ; it 

 was described from the Cumingian collection. Reeve's figure of it 

 is copied on pi. 48, fig. 43. The dimensions given by Pfeiffer are : 

 alt. 27, diam. maj. 62, min. 49 mill. 



It is from the province of Antloquia, Colombia. 



H. COXTINUA Pfeiffer. PI. 46, fig. 27. 



Umbilicated, lenticular, carinated, rather solid, striate and sub- 

 granulate, brown, strewn with whitish maculations above ; spire 

 scarcely elevated, apex fine, obtuse ; sutures nearly linear ; whorls 5, 

 nearly flat, the last acutely carinated, inflated and deflexed an- 

 teriorly, the base tumid, constricted behind the peristome, slightly 

 sulcate inside the umbilicus ; aperture very oblique, lunar, with a 

 compressed tooth on the parietal wall; peristome continuous, white, 

 callous, expanded and reflexed, the basal margin very slightly 

 arcuate. (Pfeiffer.) 



Alt. 15, diam. maj. 41, min. 35 mill. 



Province of Ocana, Colombia. 



Helix continua PFEIFFER, Proc. Zool. Soc. Lond. 1853, p. 128 ; 

 Monographia iv, p. 308. REEVE, Conch. Icon., f. 1270. 



H. FAUNUS Philippi. PL 46, figs. 21, 22, 23. 



Umbilicate, depressed, angulate, striate, subcostulate at the sutures, 

 chestnut colored ; spire scarcely elevated ; whorls 5, slightly convex, 

 the last subirregular, deflexed at the aperture and rounded, con- 

 stricted behind the peristome ; base inflated ; aperture very oblique, 

 semioval, unidentate, livid w r ithin ; peristome thick, white, reflexed, 

 margins joined by a white callous, the upper margin arcuate, the 

 basal substraightened and separated from the upper by an acute 

 tooth. (Philippi.) 



Alt. 24, diam. maj. 47, min. 38 mill. 



Mts. near Santa Fe de Bogota. 



