HELIX-PATULA. 81 



any of the allied forms. The apical whorl seems to be smooth, but 

 I saw no abrupt change in sculpture between it and the following 

 whorls ; the species is therefore a true Patula. 



P. LEPTA Westerlund. PL 30, figs. 36, 37, 38. 



Shell small, narrowly umbilicated, convex-depressed ; densely 

 and delicately membranaceously-lamellate above and below, scarcely 

 shining, yellowish-corneous, the same color above and beneath. 

 Spire convex, obtuse ; whorls 3-1-4, rather slowly, regularly increas- 

 ing, convex, separated by a profound suture ; the last whorl obtusely 

 angulated above, much more convex beneath, not descending in 

 front. Aperture large, lunate-rounded ; peristome thin, columellar 

 margin widely patulous above. Alt. 1, diam. li mill. (West.) 



Nagasaki, Japan. 



H. (Patala) lepta WEST., Vega-Expeditionens Vetenskapliga 

 lakttagelser, iv, p. 195, t. 3, f. 7, 1887. 



This little species is allied to amllygona Reinh. and flocculus Mor. 



H. LEPTOTERA Mabille & Rochebrune. PI. 21, figs. 21, 22, 23. 



Shell broadly and perspectively umbilicated, depressed, thin, pel- 

 lucid, very fragile, corneous-rufescent, a little shining, closely rib- 

 striate, and having yellowish streaks here and there. Spire sub- 

 compressed, scarcely projecting, apex very minute, eroded ; whorls 

 5-6, narrowly convex, regularly and rapidly increasing, separated 

 by a profound suture ; the last whorl large, obscurely angular at 

 its origin, not descending at the aperture, flattened beneath, obtusely 

 angulated around the umbilicus. Aperture small, round-lunate, 

 oblique ; peristome straight, simple, acute, the margins distant. 



Alt. 3, greater diam. 5, lesser 4 mill. (M. & R.} 



Orange Bay, Patagonia. 



Patula leptotera M. & R., Bull. Soc. Philom. Paris, 1885-6, p. 

 123 ; Miss. Sci. Cap Horn, Moll. p. 16, t. 6, f. 6. 



H. RIGOPHILA Mabille & Rochebrune. PI. 21, figs. 18, 19, 20. 



Shell broadly and perspectively umbilicated, depressed orbiculate, 

 thin, fragile, subpellucid, very sharply striate-costulate ; rufescent ; 

 spire flattened, apex very minute, smooth ; whorls 4, exactly rotund, 

 very rapidly and irregularly increasing, separated by a deeply 

 impressed, but non-canaliculate suture ; the last whorl large, convex- 

 6 



