3 88 



Records of the Indian Museum. [Vol. XXIV, 



, Group : Davidius. 



Number of cross-nerves between M,_ y and M 4 not so constaut, 

 and not always showing the same amount of specialization in the 

 fore-wings as in the hinder-wings. Sectors of arculus widely sep- 

 arated at their origin, constantly though slightly divergent, and 

 scarcely curved Triangle of hinder-wing with costal margin about 

 twice as long as the basal margin, its outer margin distinctly 

 angled ; often with a cross-nerve. Qu x and Cu 2 in hinder-wing 

 distinctly divergent. Pterostigma braced. Basal antenodal 

 nervure of 2nd series occasionally present. Hindermost femora 

 when adpressed reaching almost to distal end of second abdominal 

 segment (in D. davidi). Dorsum of segments 3-7 of abdomen 

 entirely black, or marked with a fine longitudinal line of yellow. 



Upper anal appendages of male each with large ventral process. 

 Lower appendage cleft at the apex, its branches not divaricated. 



Genus Davidius Selys. • 



Genotype : D. zallorcnsis Selys (?). ' 

 Species studied : D. aberrans Selys ; D. davidi assam- 

 ensis Laidlaw. 



Characters of the tribe. 



Distribution: Himalaya, Assam, Tonkin, China, Japan, Man- 

 huria. 



Davidius aberrans Selys. 



1 $. Binyar, Kumaon, 7700 ft., 24-V-1912. A. 1). I nuns, For. Zool. 

 Coll. 



This specimen has the triangles 

 of both hinder-wings crossed by a 

 single nerve, and in addition the 

 triangle of the right forewing is 

 traversed by a nerve lying parallel 

 to the long axis of the wing. The 

 triangles of the fore-wings in this 

 specimen are relatively more elong- 

 ated than appears to be the case in 

 the species figured by Ris. 



Length of abdomen 34 mm., of 

 hinder-wing 28 mm. 



K10. 9.— Colour-pattern of syn- 

 ihorax of Davidius aberrans 

 Selys, 2. 



Davidius davidi assamensis Laidlaw. 



1 S , 1 ? ?. Copaldhara Darjiling District 9-V-14. H. Stevens. 



'Dorsum of synthorax entirely black save for the small meso- 

 thoracic collar and a small extension from this running up the 

 mid-dorsal carina for about the first half of its length. 



1 Should D. zallurensis and D. aberrans prove lo be conspecific ihe laltci 

 name must take precedence, tuid the genotype would then be D. aberrans (Selys). 



