264 DRYM^EUS, SOUTH AMERICAN. 



Bulimus canaliculatus PFR., P. Z. S., 1845, p. 68; Monogr., ii, p. 

 93. REEVE, Conch. Icon., pi. 41, f. 256. Otostomus canaliculatus 

 Pfr., H. ADAMS, P. Z. S., 1866, p. 442 (from eastern Peru, Bartlett 

 coll.). 



Cousin considers this closely allied to D. nystianus, perhaps an 

 extreme variety of that species. 



D. AMBUSTUS (Reeve). PI. 46, figs. 66, 67. 



Shell nearly imperforate, ovate, thin ; white, more or less yellow 

 beneath, often rose-tinted on the spire, marked with irregularly 

 spaced narrow chestnut and yellow streaks, fainter toward the suture 

 above, and often partially interrupted by a subperipheral light line. 

 Surface shining, smooth, with faint, irregular growth striation. 

 Spire short-conic, apex with very fine but typical Drymceus sculp- 

 ture. Whorls 5J, rather convex, separated by superficial sutures ; 

 last whorl convex, somewhat tapering below. 



Aperture ovate, white or streaked within, oblique ; peristome thin, 

 sharp, unexpanded ; columella with a spiral fold above (very strong 

 in immature shells), the edge reflexed and closely appressed. 



Alt. 26, diam. 13i ; alt. of aperture 13 mill. 



Ecuador: between Jacunga [Tacunga~\ and Ambato [Ambuta] 

 (Bourcier) ; La Mocha (Paz) ; Alchipichi (Martinez) ; Tumbaco 

 (Boetzkes, Cousin) ; Cotocollas, Guapulo (Cousin). 



Bulimus ambustus REEVE, Conch. Icon., pi. 74, f. 535 (August, 

 1849). PFR., Conchyl. Cab., p. 106, pi. 33, f. 22, 23 ; Monogr., iii, 

 p. 409; viii, p. 145. HIDALGO, Journ. de Conchy]., 1870, p. 57 ; 

 Viaje al Pacifico, p. 106. Thaumastus ambustus MILLER, Malak. 

 BL, xxv, 1878, p. 193. COUSIN, Bull. Soc. Zool. France, 1887, xii, 

 p. 221. 



Allied to D. nystianus, but the base is not in the least angular, 

 the surface is smoother and the color-pattern different. The series 

 before me supports Cousin's opinion that B. chamceleon Pfr. is merely 

 a variety of ambustus. 



Var. chamceleon (Pfeiffer). PI. 46, figs. 68, 69. 



Form similar to D. ambustus, but often more slender, the lateral 

 outlines of the spire more convex. Yellowish-white with broad, 

 longitudinal stripes of purple-brown or dark chestnut, occasionally 

 not extending to the columella, leaving a small light basal area. 



Alt. 26, diam. 12-13 ; alt. of aperture 12 mill. 



Ecuador : Quito (Bourcier) ; La Mocha (Paz) ; Cumbaya, Baeza 

 and Nanegal (Martinez). 



