t>0 ODONTOSTOMUS. 



the color-tone of both aperture and surface ; and Moricand has 

 figured a specimen having a brown peripheral band, under the name 

 var. zonata (fig. 80). The pits behind the lip vary from deep to 

 slight depressions. Four of the specimens before me show a very 

 small denticle upon the parietal wall close to the groove at the root 

 of the columella. The lip generally spreads flatly, but sometimes is 

 recurved at the edge. 



Rang obtained specimens said to be from Cantagallo, and Paz re- 

 ports it from Rio Janeiro, but neither apparently collected the 

 species, so that its presence in Rio Janeiro Province requires confir- 

 mation. I doubt it. 



Subgenus SCALARINELLA 'Doering' Dohrn, 1874. 



Scalarinella Doering MS. in DOHRN, Malak. Blatt., xxii, p. 202, 

 1874, for S. stehneri Doer., = cordovanus Pfr. Clessinia DOERING, 

 Bol. Acad. Nac. Ciencias, p. 332, and Periodico Zoologico, i, pt. 3, 

 p. 201 (1875), for O. stehneri Doer. 



Shell fusiform-turreted, slender, costulate, composed of 9 or 10 

 whorls, the last carinate above and below, free in front. Aperture 

 oval, with lamelliform parietal and columellar lamellae, and com- 

 pressed upper and lower palatal folds and a suprapalatal fold. 

 Peristome continuous, expanded, free. Jaw with 15 plaits. 



An Argentine group, differing from Macrodontes by the plaited 

 jaw, numerous whorls and lamellar parietal tooth. The apical sculp- 

 ture is unknown to me, but the other known characters of the shell 

 lead me to believe that its genesis is traceable to Spixia, and that it 

 has no affinity to Macrodontes. It is a specialized form of the group 

 of 0. charpentieri. 



O. CORDOVANUS (Pfeiffer). PI. 13, fig. 100. 



Shell subrimate, fusiform-turreted, rather solid, densely arcuate- 

 costulate, the riblets somewhat decussated, shortly hairy ; pale 

 brown corneous. Spire long, the apex obtuse. Whorls 10, the 

 upper ones convex, those following perceptibly flatter, the last be- 

 coming free in front, descending, acutely carinate above, the base 

 crested and pitted. Aperture entire, oval, five-toothed: two lamelli- 

 form teeth on the left, three unequal ones within the right margin. 

 Perisrome continuous, expanded, whitish. Length 23, diam. 5, 

 aperture with peristome 6^ mill, long, 4| wide (Pfr.}. 



