40 ODONTOSTOMUS. 



II. Aperture armed with teeth, or at least a columellar fold or 

 lamella. 

 a. Parietal lamella twisted and angular, composite ; shell 



cylindric-ovate, S.-g. Plagiodontes. 



a. 1 Two teeth on the parietal wall, rarely wanting ; single 

 stout teeth on the columellar and on the palatal margins ; 

 shell short, Parta/a-shaped, with less than 5 whorls. 



Sect. 13onnanius. 

 a? Parietal lamella simple. 



b. Peristome free and continuous; whorls about 10. 



S. g. Scalarinella. 

 b.* Peristome adnate, the parietal margin thin. 



c. A groove or gutter at both ends of peristome ; 

 a sutural fold developed. 



Sect. Cyclodontrna, p. 58. 

 c. 1 No such grooves at ends of the peristome. 



d. Apex with minute grated or pitted sculpture. 

 e. Folds within the outer lip compressed, 

 entering ; rather thin, moderate 

 sized or small species. 



Sect. Bahiensis, p. 46. 

 e. 1 Large and solid species. 



Sect. Odontostomus, p. 62. 

 d. 1 Ap^x vertically costulate. 



S. g. Spixia, p. 66. 



This key is quite artificial, being based upon the most obvious 

 rather than the most stable characters. The relations of the groups 

 may be better expressed by their sequence below. 



Section Moricandia Pilsbry & Vanatta, 1898. 



Moricandia P. & V., Nautilus xii, p. 57 (Sept. 1, 1898), type 

 fusiformis Rang = dubiosus Jay. 



Fusiform species with 7-9 whorls, the last tapering and prolonged 

 below, the apex with minute, even, grating of spiral and vertical 

 riblets. Aperture angular or prolonged below in a u spout," wholly 

 without teeth or lamellse other than a low, vertical columellar fold ; 

 outer lip narrowly expanded. Type 0. dubiosus Jay. 



Distribution, Sao Paulo to Pernambuco, Brazil, in the mountain- 

 ous interior. Named for STEFANO MORICAND, an able expositor 

 of Brazilian conchology and botany. 



