1871.] MR. A. G. BUTLER ON THE GENUS ELYMNIAS. 519 



exhibit differences of a less marked character, such as will only serve 

 in an imperfect manner to separate the smaller sections of the group. 

 I have noticed that this transitional state of things often occurs in 

 genera largely acted upon by mimicry*; and I think it may be ex- 

 plained from the fact that the necessity for the various species to re- 

 semble different protected forms brings about a modification in the 

 general outline of the wing, and consequently the position of the 

 nervures employed in expanding and supporting the wing i3 liable to 

 be altered. 



Elymnias. 



Elymnias, Hiibner, Verz. bek. Schmett. p. 37 (1816). 



Melanilis (part.), Fabricius, in Illiger's Mag. vi. p. 282 (1807). 



Biblis (part.), Latreille, Enc. Meth. ix. p. 10 (1819). 



Front wings triangularly ovate ; costa arched ; outer margin den- 

 tate sinuate ; inner margin in males arched, sometimes with patch 

 of thickened scales on interno-median area. Hind wings subtrian- 

 gular, more or less dentate sinuate, the longest tooth being at end of 

 third median branch, and sometimes caudate. 



Front wings with costal nervure much swollen at base, reaching 

 middle of costa ; first subcostal branch emitted at some distance be- 

 fore end of cell, second just before end, third at first third of distance 

 from cell to apex, and the fourth and fifth forking from second third ; 

 upper discoidal emitted close to subcostal, lower discoidal obliquely 

 a little below upper, reducing upper discocellular to about one-fourth 

 the length of lower, which is strongly concave ; second and third 

 median branches emitted close together. 



Hind wings with first subcostal emitted at some distance before 

 end of cell (nearer to end in E. patna than in any others) ; second 

 subcostal and discoidal nervures emitted somewhat near together ; 

 upper discocellular horizontal, sometimes slightly oblique backwards 

 (JE. penanga, panther a, casiphone, lais, &c.) or forwards (E. 

 ceryx) ; lower discocellular about four times the length of upper, 

 strongly arched forwards (E. undularis, panthera, &c.) or back- 

 wards (E. casiphone, lais, &c). The hind-wing cell therefore ex- 

 hibits two external projections, one terminating in the second sub- 

 costal and discoidal, the other in the second and third median 

 branches. 



The species are all Asiatic, the type of the genus being E. undu- 

 laris, Drury. 



Undularis group. 



Colours. Males above black ; front wings with discal series of 

 lilac or lilac-tinted white spots ; hind wings with more or less fulvous 

 or ferruginous external area ; below, all the wings marbled with fer- 

 ruginous and whitish ; hind wings generally with a conspicuous 

 metallic subcostal spot. 



Females above tawny or brown, with discal series of white or pale 

 lilac spots ; below paler than in males. 



* Ab for instance in the genus Dismorpkia (Leptalis, auot.) of the Pierirur. 



