NO. 1571. DRAGONFLIES OF BURMA AND SIAM— WILLIAMSON. 



305 



'phus; and for G. (Aeshna) thmnassoni Kirby see Onychogomphus. 

 Gomphus f lyromelas De Selys, from India, and G am phus ? ceyloni- 

 cus Hagen, from Ceylon, are known each from a single female, in 

 the case of promelas the tyjie lacking the last 7 abdommal seg- 

 ments. In the case of each the stigma is without brace vem ; the 

 yellow dorsal thoracic stripes are isolated, not jomed below with the 

 mesothoracic half collar. Each has the abdomen about 41 mm., 

 liind wing 38-39 mm. The stigma is blackish in promelas, yellow 

 in ceylonicus; the mesothoracic half collar is scarcely interrupted m 

 promelas, widely interrupted in ceylonicus: and the dorsal stripes 

 are more widely separated from the half collar in ceylonicus than in 

 proTYielas. The two species above referred to which certainly belong 

 in the genus Gomphus are personatus De Selys, laiown from Assam, 

 Bengal, and Tonkin, and a new species described below from Burma. 



Fig. 32.— Wings of male Gomphus xanthenatus from Burma. 



13. GOMPHUS XANTHENATUS, « new species. 



Abdomen, male 45 mm.; hind wing, male 39 mm. Antenodals, 

 front wing 16, hind wing 10-12; postnodals, front and hind wings 

 11-12. Basal antenodal of second series present in the 4 wings of 

 two specimens, present in front wings and wantmg in liind wings of 

 one specimen, and wanting in 4 wings of one specimen. (In a male 

 of melsenops it is present in the front wings, wanting in the hind 

 wings; in a female of the same species it is present in one fi'ont wing, 

 wanting in the other 3 wings.) (See fig. 32.) 



o The specific name refers to the conspicuous yellow area on the ninth abdominal 

 segment. 



Pruc. N. ]M. vol. xxxiii— 07 20 



