206 ORTHALICUS. 



b. Spirally striated, though the striae are fine and shallow ; 

 form rather conically ovate. adamsoni. p. 207. 



b l . No spiral striation ; and of more fusiform contour. 



c. Spire purple, last whorl tawny or olivaceous-brownish; 

 lip black, shading into violet within ; eolumella ver- 

 tical, folded ; alt. 59-67 mill, approximatus, p. 208. 

 c 1 . Glossy, light fawn-colored usually with some dark 

 markings, spire thick below, attenuated above, lip 

 brown, purple within. powisianus, p. 206. 



a 1 . Aperture tinted within; surface rather rough, heavily blotched or 

 mottled, or with the last whorl dark throughout; peristome 

 dark brown, becoming reddish-purple within. 



atramentarius, p. 209. 

 O. POWISIANUS (Petit). PI. 37, figs. 28-34. 



Shell oblong-conic, solid and strong, light fawn colored with nu- 

 merous inconspicuous slightly darker streaks, and usually some pur- 

 plish blotches and streaks ; begirt a little below the periphery by a 

 narrow brown-black band somewhat uneven in width, and narrowly 

 light-edged in places ; this band ascending the spire, showing a little 

 at the suture ; some of the earlier whorls with a continuous or inter- 

 rupted median brown line, first whorl brown-topped ; on the last 

 whorl or two a dark line (often interrupted) borders the whitish 

 suture below. Surface polished, glossy, with faint growth-lines, 

 stronger at the sutures. Spire convexly conic below, ooncavely conic 

 above, apex obtuse, flattened. Whorls 7, the earlier 3 regularly 

 thimble-pitted, those following almost flat, penultimate and last whorls 

 slightly convex, the latler obliquely produced and spreading out- 

 wardly and downward, near the aperture, with a narrow blackish 

 streak behind the lip: the base flatly tapering to a rounded ridge 

 behind the columella. 



Apertureoblique, rhombic, somewhat effuse below, ^wre white within, 

 with a broad purple internal lip-border ; peristome obtuse and thick, 

 black-brown; columella subvertical, white, anda trifle tortuous above, 

 purple below, parieto-columellar callus brown-black. 

 Alt. 74, diam. 35, longest axis of aperture 38 mill. 

 Alt. 68, diam. 33^, longest axis of aperture 35 J mill. 

 Colombia : Marmato, and the forest on the east side of the Cauca, on 

 the road to Salamina, on damp banks under trees and on shrubs 

 (Bland); Forests on the Cauca River (Lehmann and others). 



