568 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lu 



the other showing the aedeagus which by then had been removed and 

 photographed separately. These four photographs and the original 

 description represent all of the information that I have been able to 

 gather regarding this species. 



Following his description, Meyrick noted that acanthogonus is "near- 

 ly allied" to popeanellus (Clemens), also described from Texas. Actu- 

 ally, there is little in Meyrick's description which could with certainty 

 be used to separate the two species. All of the distinctions he makes 

 easily fall within the considerable range of intraspecific variation that 

 I have observed in popeanellus. In addition, the photograph of the 

 adult is inconclusive and could easily represent an example of 

 popeanellus. 



However, the photographs of the genitaha indicate that although 

 acanthogonus is very closely related to popeanellus, it is apparently a 

 distinct species. The chief differences lie in the structure of the aede- 

 agus which, in acanthogonus, is rather elongate, slender, and almost 

 entirely unexpanded at the base. Its vesica appears to be unarmed 

 and lacks the basal and apical clusters of cornuti so prominent and char- 

 acteristic in popeanellus. In addition, the cucullus of the harpe is 

 shorter, broader, and more expanded in the apical portion than it is in 

 popeanellus. Lastly, the fm-cae of the uncus are more prominently 

 expanded dorsocaudad than in most of the examples of popeanellus 

 that I have seen. Thus, acanthogonus appears to be distinct. 



I have been unable to locate any specimens with genitalia compa- 

 rable to those shown in the photographs representing acanthogonus. 

 I have numerous specimens of popeanellus from Texas, but no example 

 of acanthogonus is among them, since dissections of these specimens 

 have consistently revealed the typical aedeagus of popeanellus. Be- 

 cause the material available seems hardly sufficient for making a prop- 

 er diagnosis of acanthogonus, I must remain uncertain of its identity 

 and proper position. It midoubtedly belongs to the popeanellus 

 species group and, on the basis of its external features and uncus, 

 would emerge with popeanellus at the same point m my key. It 

 could then presumably be separated from popeanellus by means of its 

 aedeagus. Perhaps, like Acrolophus Jervidus Busck, it is predomi- 

 nantly a Mexican species occurring only infrequently north of the 

 Rio Grande. 



13. Acrolophus klotsi, new species 



Figures 65-69 



Male. — Coloration and external structures generally similar to 

 those of popeanellus. Head, antennae, and thorax ochreous. Labial 

 palpi elongate, recurved back over head and extending almost to 

 posterior margin of thorax, densely clothed with scales, basal portions 



