12 - 13 



nodal indicator — — 



12 - q 



39 8 Records of the Indian Museum. [Voi v . XXIV, 



colour. Anterior pair of hamules, small . simple and partly con- 

 cealed between the second pair. These are large and very con- 

 spicuous, rather trigger-shaped, their apices tying ventrally to the 

 triangular vesicle. 



Length of hind-wing 35 mm., of abdomen 39+15 mm. 



Venation that of a typical Gomphus, pterostigma braced , 



1 5-12 



10-13' 



G. xanthenalus Williamson, Burma. Traces of the juxta- 

 humeral band present, a broad black band on the two lateral 

 sutures. Abdomen of ^45 mm., hinder-wing 39 mm. 



G. personahis Selys, Assam. Traces of juxta-humeral band 

 present, narrow black bands on lateral sutures, the first incomplete 

 above. 



Abdomen of cf 42 mm., hinder-wing 37 mm. 



G. ? promelas Selys, Madras. Dorsal stripes of syntliorax 

 " presque confluentes" with mesothoracic collar, no juxta-humer- 

 al stripe. Pterostigma unbraced. Exact position doubtful. Fe- 

 male only known. 



Abdomen of $ 42 mm., hinder-wing 38 mm. 



G. P ceylonicus Selys, Ceylon. Narrow isolated dorsal stripes, 

 juxta-humeral band represented by a superior spot. Pterostigma 

 unbraced. Female only known. Abdomen of 2 41 mm., hinder- 

 wing 39 mm. 



Genus Platygomphus Selys. 



Genotype : P. dolabrattts Selys, 

 Species examined: P. dolabtattts Selys. 



Differs from oriental species of Gomphus in having the anal 

 margin of the hinder- wing of the male only slightly excavated, so 

 that the anal angle of the hinder-wing is not so bold as in that 

 genus. In this respect it shows some approach to Anor mo gomphus. 

 The number of rows of cells between Cu 2 and the margin of the 

 hinder- wing is three only. The apex of the abdomen of the male 

 is more dilated than in the oriental species of Gomphus, and the 

 colouring is rather of the ' xerophilous ' type; i.e. more brown 

 and yellow than is usual in the allied forms where yellow and 

 black prevails. 



Platygomphus dolabratus Selys. 



id. 



Upper lip entirely yellow. Vertex with a diamond-shaped 

 yellow spot between the posterior ocelli, occiput yellow glabrous. 

 Dorsum of syntliorax black, with dorsal stripe reduced to a large 

 triangular spot on either side of the mid-dorsal carina. Juxta- 

 humeral band remarkably broad, complete, mesothoracic collar not 

 interrupted in middle line. Sides yellow, short dorsal black 



