PLEURODONTE. 



93 



The strong, opaque, cariuated shell, with toothless aperture, uni- 

 colored or with few, broad bands., is characteristic, as is also the very 

 long epiphallus and short flagellum, and the blunt, broad cusps of 

 the teeth. The jaAV is either smooth or ribbed, as in Caprinus. 

 A. fuller knowledge of the genitalia is necessary for the final settle- 

 ment of specific limits; meantime the following arrangement is 

 offered. 



P. caracolla Linn., v, 120. 



tornata Born. 



albilabris Lam. 



oculatus Montf. 

 P. excellens Pfr., v, 120. 

 P. insititia Shtitt., v, 121. 

 P. sarcocheila Morch, v, 121. 

 P. angistoma Fer. 



angystoma Dh. 



anchistoma v. Mart. 

 P. bornii Pfr., v, 127. 



marginella Pfr not Gmel. 

 P. bizonalis Desh., v, 127. 



v. gaskoini Pfr. v, 127. 

 P. marginella Gmel., v, 124. 



marginata Born. 



sagemon Beck. 



arangiana Poey. 



marginatoides d'Orb. 



? fasciata Blv. 



? indiscreta Beck, 

 v. gutierrezi Poey, v, 125. 

 v. schwartziana Pfr., v, 125. 

 v. mina Pfr., v, 125. 



marginata Orb. 



jactata Gundl. 

 v. rostrata Pfr., v, 1 26. 



pazensis Poey. 



cupulata Pfr. 

 v. marginelloides d'Orb., v, 126. 



transitoria Pfr. 

 v. semiaperta v. Mart., v, 125. 



Section Isomeria Albers, 1850. 



Isomeria ALB., Die Hel., p. 126, type H. oreasKoch. v. MART., 

 Die Hel., p. 155. PILSBRY, Manual of Conch, v, p. 135. 



Shell depressed, solid, opaque, chestnut or chocolate colored, rounded 

 or obtusely carinated at the periphery, imperforate or umbilicated. 

 Spire depressed, convex, with 6 or fewer whorls, the last deflexed or 

 straight in front. Aperture wider than high, very oblique ; peristome 

 expanded or reflexed, toothless or with small teeth, of which one is 

 situated near the termination of the periphery ; ends of peristome 

 remote, joined by a parietal callus, the parietal wall often having 

 an oblique tooth. Type P. oreas Koch. (pi. 25, figs. 2, 3, P. faunus 

 var. ritchieana). 



Animal unknown. 



A group of large and beautiful dark colored helices confined to 

 the valleys of the higher Andes of Ecuador and Columbia, where 



