INDIAN DRAG ON FLIES. 739 



Expanse 62 mm. Length 35 mm. (See J. B. N. H. Soc, Sept. 15, 1917.) 

 Hab. Lower Mesopotamia. 1 have not taken this insect further up the 

 Shat-el-arab than Kerna, it is common about Basra. The specimens des- 

 cribed by Ris are from Fao. It has much the same habits as the following 

 insect contammata and keeps to the banks of rivers. 



54. Brachythemis contaminata, Brauer. 



Libellula contaminata, Fabr. 

 Lihellula truncatula, Rambur, 1842. 



Male : Exp. 45 mm. Length 32 mm. 



Head : eyes violety brown above, puce, olivaceous or olive green at the 

 sides and beneath ; occiput brown ; frons and epistome a very pale green 

 almost white or in very adult specimens, olivaceous. 



Prothorax ochreous with 2 transverse brown stripes. 



Thorax olivaceous brown, darker on the dorsum ; an obscure, brown, 

 humeral fascia and 2 similar lateral fascije on the sides ; the sutures 

 black. 



Legs ochreous, the femora black externally. 



Wings hyaline, the reticulation reddish ; a rich, amber-coloured fascia 

 extending from the base outwards to the proximal end of stigma or a little 

 further. This fascia is most intense in its outer part and in some speci- 

 mens is separated from that part covering the base, usually there is a 

 variable area which is but faintly tinted between the basal and outer 

 parts. It is subject to wide variation being most intense in the wet-sea- 

 son and southern forms. In some it is almost absent. Stigma red. 

 Membrane ochreous. Antenodal nervures 8, some of them running from 

 the intercostal to the costal nervure only and others only between the 

 subcostal and intercostal nervures. Occasional nervures are bifid. 



Abdomen rich ochreous or even reddish, marked with obsolete, dorsal 

 and subdorsal stripes. In some specimens the ground colour of the abdo- 

 men is a pale greenish yellow, this colour being almost obscured by a 

 broad, subdorsal fascia on each side, which entirely covers the last 4 to 5 

 segments and expands and meets across the dorsum at the distal parts of 

 many segments. Some specimens in addition show a row of geminate, 

 narrow, black, dorsal streaks and another row of fine black streaks on the 

 outer side of the subdorsal, ochreous fascia. 



Anal appendages ferruginous. 



Female paler but the markings much better defined, especially on the 

 abdomen. Eyes a paler brown colour above. Face pale or whitish. 



Thorax a pale greenish yellow, the fascia noticed in the male being 

 darker and better defined, the humeral one forking below. Sutures of the 

 thorax and those of the first few segments of the abdomen, mapped out 

 in black. 



Wings hyaline, with no amber tinted fascia as in the male. Stigma 

 conspicuously bright yellow. 



Anal appendages paler, black tipped. 



Hab. Continental Inaia. Ceylon, Malay Peninsular, Indo-China. 



This species is invariably found along the banks of rivers or large tanks. 

 Males and females are about equal in numbers and during the daj'time do 

 not appear to molest one another, paring taking place at dusk. The insect 

 is on the wing from earliest dawn to dusk and its shadowy form may even 

 be noted hovering over water long after dark, during which hours, its 

 principal food consists of mosquitoes. 



