ODONTOSTOMUS. 59 



twisted, the others entering ; a sulural fold developed ; ends of the tip 

 separated from ttie whorl by grooves. Apex | with minutely grated 

 sculpture. 



There are three Brazilian specie.", one, 0. scabrellus, being strongly 

 ribbed, the others merely striate. 



Beck's group originally contained species of Spixia, lialilemis, 

 Gyclodontina in its present sense, and Plagiodontes, besides some in- 

 congruous exotic forms and several undetermined species. Herr- 

 mannsen in 1846 writes " typus : Pupa drap<irnaldii For. vel Ptipn 

 listen Gray." The former of these was a nude name, and had not 

 been defined in 1846; the latter is probably 0. inflatus Wagn. 

 Under 'these circumstances I h'ave thought proper to restrict Cydo- 

 dontina to 0. inflatus and related forms. Fischer had no precedent 

 for naming 0. dentutus as the type of Gyclodontina, and that course 

 is barred by the priov elimination of that species by Doering. 



O. SEXDENTATUS (Spix). PI. 11, fig. 42. 



A species resembling 0. scabreUus in contour and teeth, but differ- 

 ing in the smooth surface. Wagner describes it as cylindric-fusiform, 

 tapering and acute above, pellucid, very delicately striated longi- 

 tudinally. Whorls 10, the last narrow below and having three deep 

 transverse grooves behind the lip, with an impressed line below the 

 suture. The aperture has teeth : a parietal lamella, a large colu- 

 mellar lamella, two small folds in the base, and two within the outer 

 margin, the lower one (upper palatal) being larger. The ends of 

 the peristome are separated from the parietal wall by small grooves. 

 Color whitish, with a few separated brown streaks. Length 1 inch, 

 diam. 3^ lines (25 x 7 mill.). 



Said to be from S. Paulo province (" in provinciis S. Pauli et 

 Seb ast.ian opolitan a " ) . 



Bnlimus G-dentatns Spix, Testae. Bras., pi. 14, f. 3 (1827). 

 Odontostomus sexdentalus Spix, DOIIKX, Jahrb. d. D. Malak. Ges. ix, 

 1882, p. 106. 'f Pupa sexdentata WAGNER, t. c., p. 19. Not BuU- 

 mus sexdentatus Pfr. or Reeve. 



This description agrees completely witli 0. inflatus except in the 

 dimensions, which indicate a more slender shell. Dohrn believes 

 that even Wagner's account does not pertain to Spix's sexdentatus ; 

 in which case the species must be judged by the figure alone. This 

 is copied on my plate. 



