BULIMULUS. 137 



It varies widely in color and shape, as the figures here given show; 

 but always has conspicuously convex whorls. The interior and colu- 

 mella may he purplish-brown, ochre, or rarely white. Specimens 

 measure: Length 2l, diam. 12 mill.; 22, 10J; 24, 9J mill. 



A series of 7 shells labeled " Titicaca (A. Agassizj," are white or 

 with but few streaks, otherwise agreeing completely with those from 

 Balsas. 



B. EXORNATUS (Reeve). Vol. x, p. 171. 



Ancey reports specimens from the Andes of Bolivia east of Lake 

 Titicaca, in the Province of La Paz (Le Nat., 1901, p. 93). 



B. NIGROPILEATUS (Reeve). PI. 23, figs. 86-92. 



Vol. x, p. 182. The type was a rather small specimen with black 

 apex and a subperipheral interrupted band. A wide range of varia- 

 tion is shown in a large series taken by Baron at Cajabamba, Peru 

 (8000 ft. elev.), and others collected by Steere, exact locality not 

 noted. 



The shell may be either white, uniform or with an interrupted or 

 continuous belt below the periphery, or have additional bands and 

 lines, or there may be brown streaks in addition to the spiral bands, 

 or streaks only may be present. In any of the patterns the apex 

 varies from intense black to pale brown, corneous or translucent white. 

 The whorls are much less convex than in B. depstus. The interior 

 and columella vary from fleshy-brown to a fleshy-ochre tint, and are 

 rarely almost white. Figs. 86, 87, 88, 92 are specimens from Caja- 

 bamba ; figs. 89, 90, 91 from the Steere collection. 



B. stenacme Pfr. (Vol. x, p. 182) seems to me to be merely a form 

 of nigropileatus. An unusually long specimen from Cajabamba is 

 illustrated, pi. 23, fig. 93. 



B. radiatus Morelet (not Brug.; renamed B. angrandianus Pils., 

 Proc. Acad. Nat. Sci. Phila. 1897, p. 19), B. orophilus and B. 

 balsanus of Morelet, and B. reconditus Reeve, do not seem to differ 

 materially from B. nigropileatus, and probably are merely local 

 variations of a wide-spread species. 



B. SIMPLICULUS (Pfr.). Vol. x, p. 176. 



Specimens received from Messrs. Sowerby & Fulton under this 

 name do not differ from pruinosus Sowb. Pfeiffer's type has not 



