HELIX §. 32. 89 



541. rariplicata Bens. (Coll. 233. — Ch. ed. nov. III. 



p. 323. — liv. n. 1183. t. 174. — Patula Pfr. 



Vers. p. 126. — Discus raripUcatus Ad. Gen. 



p. 117.) Mon. III. p. 96. 



54'2. sabuletorum Bens. (Coll. 234. — C/i. ed. nov. III. 



p. 414. — Rv. n. 1180. t. 174. — Patiila Pfr. 



Vers. p. 126.) - - - 96. 



543. H. cygnea Benson. 



T. umbilicata , depressa , tenuis , oblique subdistanter 

 membranaceo-costata, diaphana, cornea; spira vix elevata, 

 apice planato; anfr. vix 47^ convexi, ultimus non descen- 

 dens, rotundatus; umbilicus conicus, fere Yg diametri aequans; 

 apertura vix obliqua, rotundato-Iunaris; perist. simplex, re- 

 ctum, marginibus subconniventibus, columellari vix dilatato. — 

 Diam. maj. 4, min. SYa, alt. I-/3 mill. (Mus. Benson.) 



Helix cygnea Bens. in Anu. and Mag. 2d. ser. XI. p. 30. 



— — Reeve Conch. ic. n. 1182. t. ili. 



— — (Discus) Pfr. Vers. p. 125. 



Habitat ad vicum Perth fluvii Cygnorum Australiae occiden- 

 talis (Bacon). 



544. H. sublesta Benson. 



T. sublate umbilicata, depressa, fere discoidea, tenuis, 

 minutissirne costulato-striata, superne rufo-cornea, subtus cor- 

 nea; spira vix elevata; sutura impressa; anfr. 4 convexiusculi, 

 ullimus non descendens, subrotundatus; umbilicus perspectivus, 

 fere Yg diametri occupans; apertura verticalis, rotundato-Iunaris; 

 perist. simplex, rectum, acutum, marginibus approximatis. — 

 Diam. maj. 31/3, min. 273, alt. \% mill. (CoII. Nr. 235.) 



Helix sublesta Bens. in Ann. and Mag. 2d. ser. XI. p. 30. 



— — Reeve Conch. icon. t. 174. f. H77. 



— — (Discus) Pfr. Vers. p. 125. 



Habitat ad urbem Freemantle fluvii Cygnorum Australiae. 



Obs. Cl. Beeve speciem delineatam operculatam et generi Cyclo- 

 stomati adscribendam esse asserit, quod e.\ speciminibus Bensonianis et 

 coUectionis meae evidenter erroneum cst. 



545. H. Mazatlanica Pfr. 



T. umbilicata, depressa, confertim costulato-striata, cornea; 

 spira parum convexa; anfr. 4 convexiuscuh, sensim accrescen- 

 tes, ultimus teres, antice vix descendens; umbilicus Va diametri 

 fere aequans; apertura obliqua, lunato-rotundata; perist. sini- 

 plex , rectum, margiuibus conniventibus . columellari supern(> 



