Most of the forms herein referred to the genus Auris have formed 

 part of the heterogeneous " genus " Bulimus of authors. I have 

 already shown the nucleus of that genus (Strop hocheilus+ Borus -f- 

 Dryptus -f Thaumastus Pils. nee auctt.) to belong to the family 

 HELICID.^E; while the genera Plekocheilus and Auris are now for 

 the first time sundered from " Bulimus," and transferred to their 

 true family position in the BULIMULIDVE. Regarding the contents of 

 the genus Auris, we must not overlook the fact that although the 

 component subgenera have never hitherto been united in one com- 

 prehensive group, yet even by Beck and Albers they are not far 

 separated in the series ; while von Martens, whose genius for per- 

 ceiving natural groups in Pulmonata we are so often compelled to 

 admire, arranges the subgenera of Auris in uninterrupted order. 



The name Auris rests upon a basis precisely similar to that of 

 of Strophocheilus (p. 4). It was proposed by Spix for two species, 

 A. melastoma and A. signata, which are placed by Wagner under 

 "Bulimus" melanostomus and "Auricula" signata. Spix's nomen- 

 clature appears also on the plate illustrating these species. No more 

 readily understood indication of the nature of Auris could be given ; 

 for good illustrations are held to define as well as the more formal 

 but frequently quite insufficient diagnosis. The later and better- 

 known name Pachyotus becomes a synonym of Auris; a fate we 

 deplore the less because the course taken by Gray in naming B. auris- 

 vulpina as type of Pachyotus, complicates the question of its use for 

 the South American group. Moreover, Gonyostomus and Otostomus 

 both precede Pachyotus in Beck's work, and the former of these 

 names would necessarily take precedence for the present genus were 

 it not for the prior and valid claim of Auris. 



I have not seen specimens of A. spectrum or dillwyniana. The 

 former of them seems to be merely a variety of A. midas. Of the 

 other species I have seen a good many specimens of all but A.perdix 

 Pfr. and A. hauxivelli Crosse, of these but few have been examined- 



The species are illustrated on plates 38-44. 



Key to Subgenera of Auris. 



I. Whorls of spire folded or plicate below sutures ; form ovate, 



AURIS, p. 98. 

 II. Whorls of spire not plicate. 



. Surface wrinkled, striate, or with long diamond-granulation. 

 b. Aperture two-thirds the alt., basin-shaped, lip with a 

 7 



