INDIAN DRAGONFLIES. 499 



Head comparatively small ; eyes brown above, paler laterally and beneath ; 

 occiput and vesicle brown ; front, epistome and labium yellowish ; basal line 

 of forehead usually present. 



Prothorax brownish yellow. 



Thorax brown with 2 broad, bright yellow, lateral stripes somewhat darker 

 above, a broad dark humeral band and black stripes traversing the spiracle 

 and metepimeron. 



Legs entirely black except the flexor surfaces of the hind femora. 



Wings hyaline or suffused with a smoky, yellow tint. Antenodal nervures 

 9| ; the discoidal field barely contracted at the termen ; a variable yellow mark 

 at the base of hindwing. 



Abdomen of male strongly constricted at the 3rd segment and fusiformly 

 dilated from the 6th to the 9th, the dorsal surface red, the ventral black. The 

 lateral borders often finely black. 



Anal appendages reddish. 



Genital organs of male ; tentaculee very large, black, the external segment 

 directed nearly horizontally back, the internal shaped as a robust, strongly 

 curved hook ; lamina procumbent ; lobe small, rectangular and directed strongly 

 backward. 



Grenital organs of female ; vulvar scale very small. 



Hab. Bengal, Assam, Khasia Hills, Burma, Thibet, Sikhim. 



36. Sympetrum orientate, Kirby. 



Diplax orientale, Selys. 



Expanse .56 mm. Length 33 mm. 

 Head comparatively small ; eyes brown above, paler at sides and beneath ; 

 vesicle and occiput brown ; forehead with a dift'use basal line present as a rule ; 

 front and epistome pale yellow. 

 Prothorax brownish. 



Thorax reddish brown on the front and dorsum, a dull reddish yellow on the 

 sides, a narrow, black humeral stripe, other markings very obscure. 



Legs entirely black or the hind femora striped with yellow on the flexor 

 surfaces. 



Wings hyaline ; discoidal field barely contracted at the termen ; basal spot 

 to hindwing moderately large, a golden yellow colour with the free border 

 not sharply defined ; antenodal nervures 8|. 



Abdomen similar in shape to hypomelas, brick red on the dorsum, black 

 ventrally. 



Genital organs of male ; tentaculse moderately large and projecting nearly 

 horizontally, the internal segment being strongly curved ; lamina moderately 

 flat but more prominent than in hypomelas ; lobe a little rounded slightly arched, 

 small. 



Gtenital organs of female ; a very small vulvar scale, 2 flatly curved pro. 

 jections from the 8th ventral plate. 



Hab. Bengal and Assam, Khasia Hills. 



The Sympetra are a group of very similar insects, whose specific differences 

 are not very marked, whose colouring is very similar and whose markings are 

 usually very obscure. The first four species are very closely related to one 

 another and a good deal of confusion has marked the history of their specific 

 valuation. Hypomelas and orientale are sharply marked off from the rest and 

 may be distinguished from one another by a comparison of their genital oi'gans. 

 They are more closely related to each other than to the first four species of the 

 group. 

 23 



