TOMIGERUS. 105 



Buonanni's figure, to which he applied the name Bonnanius bonnan- 

 ius. He was ignorant of the locality of the species and of Mr. Smith's 

 work upon it, and not only misquotes the reference to Bounanni's 

 work, but misspells his name, which Bounanni himself Latinizes 

 " Bonannus" 



Genus TOMIGERUS Spix, 1827. 



Tomigerus SPIX, Testacea Fluviatilia quae in itinere per Brasiliam 

 ann. 1817-1820, etc., coll. Dr. J. B. de Spix, legend on pi. 15, type 

 T. claMsus. 



Shell turbinate or ovate, compressed from face to back, imperfor- 

 ate, but with a long umbilical chink ; whorls 4-5, the spire more or 

 less conic, apex smooth ; last whorl compressed, with deep, oblique 

 grooves behind the peristome. Aperture somewhat triangular, 

 lateral, subvertical, seven-toothed ; parietal lamella much smaller 

 than the long angular and infraparietal lamellas ; three teeth on the 

 straightened and sloping baso-columellar margin a small supra- 

 columellar and large, entering, columellar lamella, and a basal fold ; 

 outer lip bearing a single obliquely entering palatal fold. Soft 

 anatomy unknown. Type, T. clausus Spix. 



Distribution : Eastern Brazil to Venezuela. 



This genus is allied on one hand to Plagiodontes, on the other to 

 Anostoma. The armature of the aperture is exceedingly similar in 

 all the known species. The homology of the .erect, plate-like fold 

 within the outer lip is not obvious ; it may represent the united 

 upper and lower palatal folds, or the upper palatal united with a 

 suprapalatal and a transverse barrier like that of Plagiodontes. 

 While specialized in shell-contour and armature of the outer lip, 

 Tomigerus is primitive in the distinctness of the three parietal 

 lamellae. 



Besides the following species, a u T. globuloides Mss.," from 

 Brazil, is mentioned in Paetel's Catalog. (Edit. 4, 2 Abth., p. 211). 

 No such species has been described by Mousson, to my knowledge. 



Key to Species of Tomigerus. 



1. Shell whitish with brown bands ; last whorl strongly distorted, 

 umbilical suture long and straightened. 



a. Spire depressed, low-conic ; back of last whorl corru- 

 gated, clausus. 





