NO. 1571. DRAG0NFLIE8 OF BURMA AND SIAM— WILLIAMSON. 311 



0. saunder^sii De Selys. India and Indo-China. Abdomen 37-39 

 mm.: hind wino; 31-32 mm.; male superior appendages almost as 

 long as 9 + 10, curved toward each other and downward; inferior 

 appendage about as long, in profile the basal two-thirds nearly straight, 

 the apical third turned upward, the branches slender and contigu- 

 ous; female vulvar lamina short, apex deeply euiarginate. (See figs. 

 35 and 36.) 



0. thomassoni Kirby. Hainan and Tonkin. Alar expanse 74 mm. 

 (hind wing 35 mm.) ; male superior ^ 

 appendages longer than 10, strongly 

 curved toward each other; inferior ap- 

 pendage less than half as long as the 

 superiors, the ])ranches divaricate and 

 recurved at the end. On the basis of 

 specimens of both sexes Martin takes 

 this species from GompJius and places it 

 in Onychoqomphus: his description of F'^- ai.-ONYCHOGOMPHus saundersh 



,.».', , ^ FROM Burma, a, lateral view of 



the interior appendage does not suggest male abdominal appendages, the 

 Onychogom'phus, however, and Kirby's short hairs on the appendages are 

 figure, in the pattern of the thorax, 



strongly suggests Gomphus pryeri. The details of venation in Kirby's 

 figure are probably not accurate, l)iit the anal triangle suggests 

 n yell ago m pit u s . 



The above notes have been compiled from the literature relating 

 to these species. On the same basis the following provisional key 

 has been prepared : 



n. Dorsal thoracic stripes on either side of the niiddorsal carina isolated, not joined 

 below Avith the mesothoracic halt collar. 

 b. Above described stripes short, oval. 



c. Abdominal segment 9 l)lack; abdomen about 29 mm frontalis 



re. Segment 9 with some yellow; size larger 



Vmeatus (India and Nepal) and rr'niirardtii (Java). 

 hh. Stripes longer, not oval. 

 r. Abdominal segments 3-G black, with a short basal dorsal half ring of yellow; 



abdomen and hind wing less than 30 mm modesius 



cc Segments 3-6 with more yellow: size larger. 

 d. Segments 3-6 basally about one-third yellow. 



e. Face without black markings; sides of thorax dark, with 2 oblique yellow 



bands insniplus 



ee. Face with black markings; sides of thorax yellow, sutures with black 



stripes cerasfis 



dd. Segments 3-6 largely yellowish gramminis 



aa. Dorsal thoracic stripes joined below with the mesothoracic half collar. 

 b. Abdominal segment 6 one-half or more yellow. 



c. Segments 8-10 yellow, dorsally black; femora largely yellow bisirigatus 



cc. Segments 8-10 black; femora largely black geometrinis 



