90 ODONTOSTOMUS. 



Argentina: Quebrada de Yatan, de Nieve, A<>ua de los Oscuros, 

 on the western slope of the Sierra de Aconjigasta. 



0. muhispiratus DOER., Periodico Zool. ii, pt. 4, p. 245 (1877). 



Readily known by the long, slender form and numerous whorls. 

 It varies somewhat, both in degree of elongation and in color, those 

 living on slopes exposed to the sun being paler and more calcareous 

 than those from shady places, which are darker colored. 



Group of 0. neghctus. 

 O. LEMOINEI Ancey. PI. 12, fig. 84. 



Shell rather slender, long and tapering, rather thin or somewhat 

 solid, narrowly, obliquely perforate, tawny-gray, somewhat glossy. 

 Spire long, regularly tapering to the somewhat obtuse apex. Whorls 

 9^, regularly and slowly increasing, a little convex, separated by a 

 simple and impressed suture, 4 or 5 earlier whorls nearly smooth, 

 those following marked with obsolete, oblique riblets, the lower ones 

 pallidly and irregularly vermiculate or wrinkled, the last whorl taper- 

 ing, angular around the umbilicus, scarcely ascending, flattened and 

 with a pit on the right side, oblong in form and scarcely larger than 

 the preceding whorl. Aperture distinctly oblique, irregularly oblong, 

 the outer margin angular above and below, showing teeth : a moder- 

 ate sized parietal lamella, a prominent columellar lamella, a trifle 

 twisted and simple, a large tooth opposite the rest within the right 

 margin, and a thickened callus within the sloping basal margin, 

 which joins the right margin at an angle. Peristome narrow at the 

 insertion, elsewhere thickened, expanded, and at the base, and especi- 

 ally the columella, dilated ; margins joined by a thin callus. Length 

 22, diam. 6^, alt. aperture 6 mill. (Ancey). 



Bolivia: Santa Cruz de la Sierra (Germain). 



Odontostomus lemoinei ANCEY, Journal of Conchology vii, p. 93, 

 fig. 1 on p. 97 (July, 1892); Le Naturaliste, August, 1892, p. 178. 



Form brevior Anc. Shorter and relatively broader, the aperture 

 larger, whorls 9. Length 18^, width 6J, alt. aperture scarcely 6 mill. 

 (Anc.). 



This form, quite a new one for Bolivia, is distinguished at a glance 

 from similar species, such as 0. achalanm Doering, known to inhabit 

 the Argentine Republic (Anc.). 



