74 ODONTOSTOMUS. 



O. KL'IINHOLT/IANUS (Cl'OSSe). PI. 12, figs. G8, 09. 70. 



Shell small for the genus, narrowly umbilicnte and openly riniate, 

 buff-white, cylindrical-fusiform, the lower three whorls of nearly 

 equal width, those above forming a slowly-tapering cone, the apex 

 obtuse. Whorls 9, the earlier 7 convex, the last two but. slightly 

 convex ; first two whorls smoothish, the rest closely and regularly 

 rib-striale, the riblets rarely dichotomose, mostly simple ; the last 

 whorl with a broad dent or excavation behind the outer lip, and a 

 deep curved groove, sub-basal in position. Aperture small, vertical, 

 nearly one-third the length of the shell, contracted by six teeth : one 

 curved entering parietal lamella; a contorted, deeply-entering colu- 

 mellar lamella, and three folds within the outer lip, one (lower pala- 

 tal) almost basal, a larger one (upper palatal) in the middle, a slightly 

 smaller suprapalatal fold just above it. At the junction of the outer 

 lip with the parietal margin there is a narrow sinus, defined by a 

 fold on- the lip and a callus on the parietal wall. 



Length 17.5, diam. of last whorl above aperture 5.7 ; length of 

 aperture 5.7 mm. 



Length 17, diam. G, aperture 5 mill, long (Crosse). 



Uruguay : Montevideo (P. Paz ; J. Arechavaletta). 



Bulimns kuhnholtzianus CROSSE, Journ. de Conchyl. 1870, p. 301 ; 

 1871, p. G4, pi. 4, f. 3. PFR., Monogr. viii, p. 10G Odontostomus 

 kuehnholtzianus DOERING, Periodico Zoologico ii, pt. 4, p. 243. 0. 

 kuhnholtzianus PILSBUY, Proc. Acad. Nat. Sci. Phihi., 1900, p. 393, 

 pi. 12, f. 12. 



Compared with 0. scabrelluni Anth., this species differs in the far 

 finer costulation, less tapering form, absence of a basal fold, larger 

 size of the suprapalatal fold, etc. 0. charpentieri Graf, is a more 

 lengthened and much less strongly costulate shell, with smaller aper- 

 ture and no posterior channel or sinus. 



O. LEPTODON (Martens). 



Shell perforate, turreted-fusiform, costulate, white, marked with a 

 few pale gray vai-ices. Whorls 9, a little convex, the last slightly 

 compressed at the base. Aperture occupying one-third the length 

 of the shell, slightly oblique, ovate-elliptical, 5-toothed : one corn- 

 pressed and entering on the parietal wall; the second strong, com- 

 pressed and obliquely descending on the columella; and three folds 

 within the outer lip, the median one stronger, upper and lower ones 



