80 ODONTOSTOMUS. 



Length 12, diam. 3f, length of aperture 3^, width 2^ mill. 



Length 12J, diam. 3f, length of aperture 3, width 2f mill. 



Argentina : Pampa de Olain, Sierra de Cordova, at 900 meters 

 elevation (Dr. Stelzner). 



0. olainensis DOER., Bol. Acad. Cienc. Cordova, 1875, p. 454 ; 

 Periodico Zoologico i, pt. 3, p. 192 (1875). B. olainensis KOBELT, 

 Nachr. d. D. Malak. Ges. viii, 1876, p. 5. PFR., Monogr. viii, 

 p. 610. 



A strongly characterized species, differing from all others in the 

 more irregular aperture, uniform corneous-whitish color, a little 

 transparent, and the very irregular teeth. The striation is very 

 fine. 



O. CHAMPAQUIANUS DoeHng. 



Shell rimate, small, fusiform-turreted, brown-corneous, roughened 

 by close rugulose striae, reticulate-variegated by elevated, membran- 

 aceous spiral lines. Whorls 9, a little convex ; the first, convex, very 

 closely striate. those following roughened by little-elevated, mem- 

 branous lamellae arranged in spiral lines ; the last whorl about one- 

 fourth the total length, scrobiculate in front, two-crested at the base. 

 Aperture subpentagonal, nearly closed by five teeth and lamellae : a 

 twisted lamella on the parietal wall, a bifid one on the columella, a 

 small tooth within the base, with a fourth strong tooth and a fifth 

 small one within the outer lip; frequently a sixth tooth projecting at 

 the upper part of the right lip. Peristome expanded, acute, thick- 

 ened within, the right lip angulated above, columellar margin a little 

 reflexed, the margins joined by a thin callus. Length 15-16, width 

 4, aperture with peristome 4 mil!, long, 3 wide (Doer.). 



Argentina : widely spread on the southwestern slope of the Sierra 

 de Achala ; granitic hills of the eastern slope of the Sierra de 

 Aconjigasta, around None ; Quebrada del Rio de Mjna Clavero, ex- 

 tending to the southern extreme of the Sierra de Achala, occurring 

 at the Quebrada de Oyada, in the province of S. Luis. 



0. champaquianus DOER., Periodico Zool., ii, pt. 4, p. 249 (1877). 



This species has some resemblance to 0. profundidens, found on 

 the north of the S. de Achala ; but it differs at first sight by the spiral 

 lines formed of fine lamella, very delicate, fragile and membranous, 

 forming a reticulate sculpture. The shell is more compact and 

 narrow, the whorls much more convex, and there are differences in 

 the teeth. 



