666 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.49. 



points on the hind femora of the male, is not constant in authentic 

 material named by him and the differentiating characters mentioned 

 in his descriptions are very shght, the length of the ovpositor being 

 apparently the only discernable difference. 



CEUTHOPmLUS ALPINUS Scudder, 



This species is also very close to califomianus and in both these 

 species as well as in vinculatus, nodulosus and a new species herein 

 described as C. genitalis, and perhaps others, the second segment of 

 the hind tarsus is no longer, or barely longer, than the vertical depths. 



CEUTHOPmLUS GRANDIS Scudder. 



This is inseparable from C. gracilipes Haldemann. 



CEUTHOPmLUS STYGIUS Scudder. 



This is but a variety of gracilipes, the only separating character 

 seeming to be the proportional length of the legs and the armature 

 of the hind femora, characters useless in this instance through vari- 

 ation. Typical stygius has the hind femora armed beneath with 

 serrations only while in gracilipes they are armed with distinct 

 spines. But a series of specimens shows a gradual variation from 

 one form to the other. Stygius has been considered a cave dweller, 

 but some years ago I took specimens beneath stones some distance 

 from caves in Indiana that were inseparable from ones taken within 

 the Wyandotte cave. 



CEUTHOPmLUS ATER Scudder. 



This species has a dorsal spine near the middle of the anterior 

 tibiae, proving it a member of the genus Useopsylla where it is placed 

 in the present paper, in synonymy under U. nigra Scudder. 



CEUTHOPHILUS POLITUS Scudder. 



This is also a member of the genus Udeopsylla and a synonym of 

 U. rohusta Haldemann. 



CEUTHOPHILUS CELATUS Scudder. 



This is not a Ceuihopliilus but belongs to the allied genus Pristo- 

 ceuthophilus, where it will be found in the present paper. 



The species of CeuthopMlus recorded by Scudder from Victoria, 

 British Columbia, as C. celatus was not this species, but C. agassizi 

 Scudder. This fact was determmed by examining a male in the Morse 

 collection from the same catch as the female in the Scudder collection. 



CEUTHOPHILUS DEVIUS Scudder. 



This species belongs to Udeopsylla and is here transferred to that 

 genus. 



