IQ22.] F. F. Laidlaw : Indian Dragon/lies. 411 



Costal nerve lined with yellow as far as the nodus (? colour line 

 disappearing in more mature specimens). 



Female. Colouring much as in the male ; but the costal nerve 

 is black (the specimen is much more mature than the male) and 

 the dorsum of the tenth segment of the abdomen is black. 



The occiput is without dentellations, but has a fringe of long 

 black hairs. The length of the vulvar scale, reaching to the end 

 of the tenth segment, is very remarkable. 



Length of abdomen of & ? -f-3.5 mm., of hinder- wing 32*5 

 mm. ; length of abdomen of 9 38 mm ,, of hinder-wing 34^5 mm. 



The two followiug species are known onty from female speci- 

 mens or from imperfect males, and I have not attempted to place 

 them in any definite group. 



0. annularis Selys, North Burma. Dorsum of synthorax 

 with dorsal stripes confluent with the mesothoracic collar, vestiges 

 of the juxta-humeral stripe present. Described from two males, 

 both imperfect. This species may belong to the geometricus group. 

 Length of abdomen 37 mm., of hinder-wing 32 mm. 



0. maclachlani Selys, North Burma. De Selys suggests that 

 this may be the female of the last species. It is larger, lacks 

 any trace of the juxta-humeral stripe, but otherwise, except for 

 details of colouring of the head, is very similar. Length of abdo- 

 men 43 mm., of hinder-wing 38 mm. 



Another species, known only from the female, is 0. cerastes 

 Selys, from Nepal. This from its largely yellow colouring would 

 seem to be rather a ' xerophilous ' species, like 0. grammicus. It is 

 possibly allied to the female next described. 



Onychogomphus sp. 



i$. Kumaon, W. Himalayas, 22-vii-i.j. (8343/20) (Lacking abdo- 

 minal segments 4-10.) 



Differs from other species of the genus (except 0. cerastes 

 Selys, and 0. grammicus Selys) that I have seen in having many of 

 the cross-nerves of the wing whitish-yellow in colour. This is 

 particularly the case with the rows of cross-nerves in the areas be- 

 tween the subcostal nerve and M 4 proximal to the nodus, and with 

 the cross-nerves of the cubital space. 



Head. Upper lip yellow, with fine black line at base. Ante- 

 aud post-clypeus 3'ellow, the latter separated from the f rolls by a 

 transverse black line. Frons yellow, its extreme base black. 

 Vertex black, with a small yellow spot between the posterior 

 ocelli. Occiput yellow, its posterior margin slightly undulated. 



Prothorax black, its anterior and posterior margins lined with 

 yellow. 



Synthorax. Dorsum black, mesothoracic collar entire, joined 

 by the lower ends of the dorsal stripes. Juxta-humeral stripes 

 complete. Sides of synthorax yellow, with narrow black line on 

 each of the lateral sutures. 



