ODONTOSTOMUS. 83 



Shell cylindric-fusiform, brown-corneous, slightly shining, minutely 

 striate, generally somewhat variegated with whitish, interrupted, 

 irregular striae. Spire fusiform-turreted, the apex a little obtuse ; 

 whorls 9, a trifle convex, the last one-fourth the total length. Peri- 

 slome white, thick, the margins joined by a compressed callus. 

 Length 13-14, diam. 3^-4, aperture with peristome 3^ mill, long, 

 2f wide (Doer., Boletin, p. 456). 



Argentina: Valle del Rio Primero, in the Sierra Chica de Cordova, 

 under stones. 



0. pucaranus DOER., Bol. Acad. Sci. Cord., p. 456 (1375). 0. 

 pucuranus DOER., Periodico Zool. i, pt. 3, p. 183 (1875) B. puca- 

 ranus Doer., KOB., Nachrbl., 1876, p. 8. PFR., Monogr. viii, p. 612. 

 B. pucuranus KOB., Jahrb., 1878, p. 134. 



Close to 0. tumitlorum in contour, but the aperture is narrower, 

 the teeth and peristome less thick. The shell is more fragile, gener- 

 ally of a dark color, a little transparent, smooth and shining; more 

 rarely there are some sparse chestnut spots. 



O. RIOJANUS Doering. 



Shell ri mate-perforate, fusiform, the apex attenuated, a little 

 obtuse; scarcely shining; ashen-whitish, with scattered dots and spots 

 of pellucid ashen; closely rugose-striate, and ornamented with some 

 longitudinal ashen-corneous spots. Spire conic, the apex attenuated, 

 a little obtuse. Whorls 9, a little convex, the first corneous-brown, 

 rib-striate the rest ashen-whitish, spotted, closely wrinkle-striate, 

 often variegated with obsolete lines; the last whorl one-fourth to one- 

 third the total length, nearly smooth, with scattered zigzag clear 

 corneous markings, becoming whitish anteriorly, somewhat im- 

 pressed at the side, the base obsoletely and shortly two-crested. 

 Aperture angularly oblong-oval, obstructed by 5 teeth : one on the 

 parietal wall, a second horizontal one on the columella, another 

 within the base, the fourth and fifth teeth small, within the outer 

 lip. Peristome white, somewhat thick, thickened within, the right 

 margin arcuate above, lower and columellar margins broadly ex- 

 panded, a little reflexed, the margins joined by a thickened, 

 depressed, lamelliform parietal callus. (Doering, Per. Zool.) 



Length 18f, diam. 5f, length of aperture 5^, width 4 mill. 



Length 19^, diam. 6, length of aperture 5J, width 4 mill. 



Length 21, diam. 6 to 6J, length of aperture 5^, width 4^ mill. 



