286 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXIII. 



Genus HAGENIUS De Selys. 



In addition to the American hrevistylus De Selys, Martin has 

 described a second species, gigas, from Tonkin. Martin's species is 

 much the larger of the two, having the abdomen 71 mm. and the 



Fig. 12.— Wings of male Hagenius brevistylus from North America. 



hind wing 54 mm., and the dorsal thoracic stripes are joined with 

 the mesothoracic half collar and not isolated as in brevistylus. (See 

 fig. 12.) 



Genus DAVIDIUS De Selys. 



The species of this genus are all small or of moderate size, ranging 

 from abdomen 29 mm. and hind wing 27 mm. to abdomen 44 mm. . 

 and hind wing 40 mm. There is great indefiniteness throughout the 

 genus in the development of cross veins in the triangles. In nanus 

 De Selys, from Japan, the triangles of all 4 wings were crossed in the 

 first female studied by De Selys; later material had the triangle of 

 front wing free and triangle of hind wing crossed and the supertri- 

 angle, normally free, accidentally crossed. Of hicornutus De Selys, 

 from Japan, only one female has been described, and this has the 

 triangle of front wing free and triangle of hind wing crossed. D. 

 davidii De Selys, known from two females from Tliibet, has the tri- 

 angle of front wing free, of hind wing crossed. D. ater Hagen, from 

 Japan, has the triangle free in all 4 wings, excepting that it is crossed 

 in one hind wing of a female. D. frulistorferi Martin, from Tonkin, 

 in 6 specimens has the triangle of front wing free, of hind wing crossed; 

 in a seventh specimen, female, all the triangles are crossed. D. aber- 

 rans De wSelys, known fTom a single female from the north of India, has 

 the triangle of one front wing free, the other triangles crossed. D. 

 zallorensis Hagen, Himalaya, known from a single male, has the tri- 



