1906.] NATURAL SCIENCES OF PHILADELPHIA. 11 



rostrum, and the more fenestrate wings of the male ; from Truxalis in 

 the longer, more produced rostrum, the more angulate caudal 

 margin of the pronotum, the slender caudal limbs and the broader, 

 less subequal tegmina; from Orphula in the characters which 

 separate it from Truxalis. The genus Hyalopteryx appears to con- 

 nect two extremes of the series, one extreme represented by Radi- 

 notatum, a quite peculiar type, and Achurum, and the other by Truxalis 

 and Orphula, Eutryxalis apparently sharing the intermediate position, 

 but really being closer to Truxalis. The sequence of genera which 

 appears most natural in the Hyalopteryges is- 



Radinotatum McNeill. 



Achurum Saussure. 



Hyalopteryx Charpentier. 



Eutryxalis Bruner. 



Truxalis Fabricius. 



Orphula Stal. 



Hyalopteryx rufipennis Charpentier. 



184.5. Hyalopteryx rufipennis Charpentier, Ortliopt. Descr. et Depict., 

 tab. 46. [Brazil.] 



Sapucay, Paraguay. December 13, 16, 19, 1904. March 7, 1902. 

 February 13 and 15, March 6, 7 and 9, 1905. (Foster, Hebard Coll.) 

 Eleven d'd', eleven 9 9. 



These specimens appear from Charpentier's description and figure 

 to be the same form as he called rufipennis. The description particu- 

 larly mentions the distinct lines on the metazona, and states that the 

 lateral carinse are similar to the median, which would hardly have 

 been said if the metazona was irregularly lineato-rugose and the lateral 

 carinse faint and strongly expanded on the metazona, as in the new 

 species here described as H. asinus. Of the caudal femora he says: 

 "Die Hinterschenkel .... oben eine fein erhabene Linie, die vorn 

 am Knie in eine ganz kleine Spitze ausgeht, woselbst seitwiirts zwey 

 weit grossere hervorragen, wie Stacheln." From this and the com- 

 parative proportions of the structures mentioned above and the sub- 

 genital plate as figured in his plate it is very evident that the Sapucay 

 specimens are either Charpentier's rufipennis or a very closely related 

 new species. Burr's H. exaggerata,^ the only other previously de- 

 scribed species, possesses elongated genicular structures as in my new 

 asinus. 



The series examined is quite uniform, a little variation in size being 



* Trans. Ent. Soc. London, 1902, pt. II, p. 183. [Chiquitos, Bolivia.] 



