156 FORPHYROBAPHE. 



tricose, 69-75 mill, long, 35-37 in diameter, the last whorl being 

 longer than the spire." (Miller.} 



"Among the examples from Nanegal great variation occurs, as well 

 in form as in coloration. The following measurements of three shells 

 illustrates the former : 



"Alt. 78, diam. 45, length of aperture 46, width including peri- 

 stome 29 



"Alt. 69, diam. 35, length of aperture 40, width including peri- 

 stome 25. 



"Alt. 70, diam. 39 J, length of aperture 41, width including peri- 

 stome 28. 



" In respect to coloring, the peristome is sometimes yellow, some- 

 times rose-red ; the ground-color of the shell is sometimes uniform 

 yellowish, sometimes dark clouded, the upper whorls either yellowish- 

 brown or dark violet-brown or white. 



"A variety from the valley of the Rio Cinto at Pichincha, 1300 

 meters alt., is quite unicolored, with stronger parietal callus, but no 

 nodule in the upper angle of the mouth." (Martens.) 



The jaw, according to Schacko, is similar to that of Orthalicus 

 obductus, composed of 17 plates, the median one triangular. The 

 teeth are of the form usual in the 0. undatus group, except that the 

 laterals are more massive, closely crowded and quadrangular. 



Miller describes two varieties : 



Var. ELONGATA Mill. (pi. 52, fig. 33). Last whorl hardly as long 

 as the spire ; peristome very strongly thickened and broadly reflexed. 

 Whorls 6|, alt. 75, diam. 30, aperture 35 mill, long, 17 wide inside. 



Pilaton Valley (Boetzkes); Los Puentes, near Gualea, in abund- 

 ance (Cousin). 



Var. MINOR Mill. (pi. 52, fig. 35). Whorls 6 ; alt. 58, diam. 26, 



aperture 28 mill, long inside, 14 wide. 



Pilaton Valley. 



P. GREVILLEI ("Sowerby" Pfeiffer). PI. 53, figs. 38, 39, 40, 41. 

 Shell ovate-acuminate, moderately solid. Yellow, with occasional 

 (variceal) brown streaks, and numerous irregularly scattered brown 

 spots sometimes shadowed on the side toward the lip with paler yellow. 

 Surface slightly shining, coarsely plicatulate, puckered beneath the 

 sutures, and decussated by wide-spaced spiral lines, cutting the sur- 

 face-wrinkles into long granules. Spire rather slender, the lateral 



