S PROCEEDINGS OF THE NATIONAL MUSEUM vol. 68 



BRACHYCISTIS (BRACHYCISTIS) IDIOTES Cockerell 



A large slender species with the same form of hypopygium as 

 noctivaga, in fact there are no outstanding distinctions between these 

 •organs in any of the four species of the group, all of which I have 

 examined. The characters listed in the key appear to warrant the 

 specific separation of the four forms. The inner one of the paired 

 processes of hypopygium (vSagitta of Bradley) is shorter than in 

 mormalis (fig. 43), otherwise the hypopygium is similar. 



Length, 15-18 mm. 



Originally described from Las Cruces, N. Mex. I have seen it 

 from Keeler, Calif., November 14, 1914 (A. Wetmore). 



BRACHYCISTIS (BRACHYCISTIS) NOCTIVAGA Bradley 



A much stouter species than the last, the first abdominal segment 

 Toeing conspicuously stouter. The quite conspicuous elevation of the 

 gular carina at its anterior extremity (fig. 30) readily separates this 

 species from the next two, but in this character it is similar to idiofes. 



Length, 12-14 mm. 



Originally described from Las Vegas, Nev. I have before me 

 specimens from Arlington, Higley, and Mount Superstition, Ariz., 

 and one from Utah without more definite locality. 



BRACHYCISTIS (BRACHYCISTIS) AEQUAUS Fox 



This species has the first abdominal segment more elongate than 

 in noctivaga or normalis, and in the specimen before me there is an 

 irregular transverse carina on first tergite just behind the spiracles. 

 The occiputal carina in this species is as shown in Figure 29. The 

 marginal cell of fore wing is about as long on costal margin as the 

 stigma. 



Length, 12 mm. 



Recorded from Colorado, Nevada, and Arizona. The only spec- 

 imen I have seen is from Arizona. 



BRACHYCISTIS NORMAUS, new 8pe<-ie8 



Male. — Similar to noctivaga in all respects except the structure of 

 the gular carina. Hypopygium as in figure 43. 



Length, 12-14 mm. 



Holotype. — Cedar Pass, S. Dak. (W. H. Over). ParatypCvS, two, 

 San Simon, Ariz. (Hubbard), one, Colorado (C. F. Baker), one, Los 

 Angeles county, Calif. 



Type.— Cat. ^o. 27909, U. S. N. M. 



