ODONTOSTOMUS. 59 



twisted, the others entering ; a sutural fold developed ; ends of the lip 

 separated from the irhorl by grooves. Apex | with minutely grated 

 sculpture. 



There are three Brazilian species, one, 0. scabrellus, being strongly 

 ribbed, the others merely striate. 



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

 Cyclodontina in its present sense, and Playiodontes, besides some in- 

 congruous exotic forms and several undetermined species. Herr- 

 mannsen in 1846 writes u typus : Pupa draparnaldii Fer. vel Pupa 

 listeri 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 have thought proper to restrict Cyclo- 

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

 for naming 0. dentatus as the type of Cyclodontina, and that course 

 is barred by the prioi- elimination of that species by Doering. 



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



A species resembling 0. scabrellus 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 6 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 astian opolitan a"). 



Bulimus 6-dentatus Spix, Testae. Bras., pi. 14, f. 3 (1827). 

 Odontostornus sexdentatus Spix, DOIIRN, Jahrb. d. D. Malak. Ges. ix, 

 1882, p. 106. T t Pupa sexdentata WAGNER, t. c., p. 19. Not Buli- 

 mus sexdentatus Pfr. or Reeve. 



This description agrees completely with 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 copie.d on my plate. 



