214 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 106 



number of genualae in the first leg separates E. trigenuala from 

 the "pipistrelli-oregonensis-samboni" group. The striated leg setae 

 have some usefulness at the level of the species. E. luteodema is 

 quickly separated from E. marmotae by the absence of genualae 

 II and III. The mastitarsala on the third leg of E. nunezi is 

 unique in North American Euschongastia. It might easily be one 

 of the characters of a distinct group. 



Another character of basic importance is the number of prongs 

 on the palpal claw. The diagnostic value of this character was 

 first recognized by Ewing (1938). He used it to separate the 

 two genera Neoschongastia and Euschongastia. Neoschongastia 

 was diagnosed as having two or three prongs on the palpal claw ; 

 Euschongastia was diagnosed as having more than three prongs. 

 Ewing (1946b) separated Ascoschongastia from Neoschongastia. 

 Ascoschongastia was diagnosed in part as having two or three 

 prongs on the palpal claw. Wharton (1948) rejected Ewing's 

 diagnosis of Ascoschongastia and gave a new diagnosis to 

 Euschongastia. By the new diagnosis certain species with two or 

 three prongs on the palpal claw, formerly placed in Ascoschon- 

 gastia, were included in Euschongastia, which, as stated above, 

 had been diagnosed originally as having more than three prongs. 

 Since the diagnosis of Euschongastia accepted for this paper is 

 basically Wharton's, it is obvious that the number of prongs on 

 the palpal claw is a systematic character useful in separating 

 groups of species. 



Following the fundamental divisions based on the two char- 

 acters discussed above, a variety of characters are useful. The 

 nonspecialized setae of the gnathosoma, the various leg setae, 

 and the body setae are important. The scutum and the sensillae 

 often are distinctive. Various ornamentations occur consistently 

 in different species. The number of eyes and the development of 

 the eyes are useful in a few instances. Color is helpful, but it 

 cannot be determined from a mounted specimen. Size and shape 

 are subject to change in preservation on slides and can be used 

 in few species. However, color, size, and shape are potentially 

 useful in identification of living material, particularly unengorged 

 specimens. 



Differences have been found in the number of setules on the 

 setae of the gnathosoma among the species included in this paper. 

 These setae are recognized by all workers in the genus who in- 

 clude at least some of them in descriptions and diagnoses. In the 

 present study the galeal seta and the lateral seta on the palpal 

 tibia were selected for special consideration. Whenever the num- 



