t)88 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXVII. 

 Genus — Idionyx, Selys. 



Fig. 5. Wings of Idionyx optata, female, (x 3). 



Head large, globular ; eyes broadly contiguous ; occiput small ; vesicle promi- 

 nent. 



Prothorax small, posterior lobe small, entire. 



Thorax small, narrow, finely hairy. 



Abdomen moderately long and slender, laterally compressed, the base a little 

 tumid, the terminal segments dilated (but not so in the female). Oreillets pre- 

 sent on the sides of the 2nd abdominal segment, with equal divisions. 



Wings : the fore narrow, the hind very broad, notched at the base in the male, 

 rounded in the female ; all trigones entire, subequilateral, that of hindwing, 

 distad of arc, which is situated in the forewing between the 1st and 2nd antenodal 

 nervures ; sectors of arc fused for a long distance ; antenodal nervures in the fore- 

 wing 11 to 14, postnodals 5 to 7 ; hypertrigone in the foremng traversed once, 

 that of hind entire ; subtrigone of forewing one-celled and 4 sided ; 1 cubital 

 nervure in the forewing, 2 in the hind ; 2-3 supplementary nervures to the bridge 

 in both wings ; only 1 row of discoidal cells for nearly as far as the termen (con- 

 siderably longer than in Fhyllomacromia) ; 4th (nodal sector) nervure moderately 

 convex beneath the stigma ; 5a (Rspl) strongly developed in the hindwing, 7a 

 (Mspl) obsolete ; 1 row of cells between 5 (subnodal sector) and 5a ; anal loop 

 short and stunted, its outer Hmit in line with the outer end of the trigone, com- 

 posed of 7-8 cells ; anal border broadly rounded in the female, notched in the 

 male ; stigma small, sublozenge-shaped ; membrane small. 



This genus is closely related to Phyllotnacromia by the form of the trigones and 

 the single row of discoidal cells but in Phyllomacromia the abdomen of the female 

 is dilated and the wings present a few different characters, viz., the arc is situated 

 between the 2nd and 3rd antenodal nervures (instead of between the 1st and 

 2nd as in Idionyx), and the single row of discoidal cells runs for a much 

 shorter distance than in Idionyx. 



11. Idionyx optata, Selys, Buul. Acad. Belg. XLV, 1878. 

 Id. Ann. Mus. Genov, 1891. 

 Martin, loc. cit. 1906. 

 Abd. : c? 32-33 mm., 2 32 mm. : hindwing: J 32-33 mm., 2 32 mm. 

 Male : head ; labium and labrum yellow, the latter bordered with greyish 

 brown, epistome and elypeus olivaceous, upper part of front and the vesicle 

 metallic green ; occiput and back of eyes glossy black, the latter presumably, 

 some shade of emerald or bottle green during life. 

 Prothorax dark olivaceous. 



