673 

 INDIAN DRAGON FLIES 



BY 



Major F. C. Fkaser, I. M.S. 



(^With 5 Text-p'<jures.) 



(Continued from page 498 of this Volume.) 



Part X. 



Family— LIBELLULIDAE. 



Subfamily II. — Corduliin.^. 



Compared with the Libelluhnse, the CorduliinEe are a comparatively small 

 subfamily, represented witliin Indian limits by five genera and eleven species. 



The subfamily is split up into two groups — Cordulia and Macromia, and these 

 again into genera, of which the first group contains only one genus — Hemicordu- 

 lia, and the second group four genera — Macromia, Epophthalmia, Phyllomacromia 

 and Idiomjx. 



They are usually insects of large size with robust or slim bodies with mon; or 

 less metallic colouring. The eyes are more or less contiguous, the thorax bulky 

 and the abdomen long and cyhndrical. They may be mistaken for LibellulinEe 

 or even for .^schninse, the general facies being a combination of the characters 

 of the two subfamilies. From the former they may be recognised by the follow- 

 ing chai'acters : — 



1. A small, sinuous projection on the middle of the hinder border of the eyes. 



2. A tuft of hairs or sjjines at the distal end of the anterior femora and a 

 keel on the tibiae. 



3. The anal border of the hindwings in the males deei^ly notched (except in 

 Heinicordulia). 



4. A general metallic colouring of the head and thorax. 



From the JEschnince, thej' may be recognised by the triangular arrangement 

 of the ocelli around the vesicle, and by the very marked inecj^uality of the tri- 

 gones of the fore and hind ■wdngs. 



Among the Indian Libellulince, the only one likely to be confused with the 

 Cordulines is Zygonyx iris, but in this the hindwing is not notched, the tibiie 

 are not keeled and there is no postocular projection. 



The same may be said for other metallic sjjecies, such as — Cratilla metalUca, 

 Brachydilax sobrina and farinosa and some species of Rhyolhsmis. 



Tillyard divides up the subfamily into five tribes and two of these again into 

 series, but as only three of these tribes are represented within Indian limits, it 

 is more convenient to adopt a modification of Martin's classification. 



Ctboups of Cordulines. 



A. Trigone of the liindwing in line with or 



slightly proximal to the arc. . . . . . Cordulia. 



B. Trigone of the hindwing distal to the arc . . 3Iacrotiiia. 



DiCHOTOMOus Key to the Genera and Species 

 OF THE Subfamily Corduliin.e. 



f Genus Hemicordulia. Trigone of the liindwing 

 in line with or slightly proximal to the arc. 

 1-^ Only one species within Indian limits .. Hemicordulia asiatica, 



Selys. 

 [^Trigone of the hindwing distal to the arc . • 2 



