ON NEW AND LITTLE-KNOWN BUTTERFLIES. 273 



10. CYANIRIS CORYTHUS, n. sp., PI. 0, Figs. 16, $ ; 17, $. 

 Habitat : Battak Mountains, N.-E. Sumatra. 

 Expanse: $, 1*40 to 1"50 ; $, 1*45 inches. 



Description : Male. Upperside, both wings pale shining blue. 

 Foreioing, the costa with a black marginal thread, the outer margin 

 narrowly black, the inner angle white ; a large discal oval white area 

 crossed by the blue veins occupying the lower outer end of the 

 discoidal cell, the lower discoidal, both median, and part of the 

 submedian interspaces. Hindwing with the discal half of the wing 

 white crossed by the blue veins ; a fine anteciliary black thread. 

 Cilia of the hindwing broad, white ; of the forewing white at the 

 inner angle, becoming black towards the apex. Underside, both wings 

 white faintly tinted with blue ; all the markings small, black, 

 prominent ; the usual marginal series of black dots, with a more 

 or less incomplete series of lunules within. Forewing with a fine 

 disco-cellular line ; a discal series of three, four, or five small spots. 

 Hindwing with three or four basal dots, a fine disco-cellular line, the 

 usual irregular discal series of spots, but all of them small. Female. 

 Upperside, forewing dull black, the base very faintly glossed with 

 metallic blue ; a very large oval pure white patch occupies the middle 

 of the wing. Hindwing with the costa as far as the subcostal nervure 

 and its first branch and a very small area at the base dull black, the 

 rest of the wing pure white ; a very fine black anteciliary thread, just 

 within which is a series of six lengthened oval black spots, the four 

 towards the anal angle crowned with a fine black lunule, which is 

 continued along the veins till it unites with the anteciliary thread. 

 Cilia of the hindwing pure white, of the forewing white posteriorly 

 fuscous anteriorly. Underside, both wings coloured and marked 

 precisely as in the male. 



This is a very lovely and distinct species, with no near ally. The 

 male is a little like C. ceyx, de Niceville,* from Java, but is much 

 larger ; the upperside is of a different shade of colour, more blue ; 

 the white area on the forewing is larger, that on the hindwing smaller 



* Journ. Bomb. Nat. Hist. Soc, vol. vii, p. 328, n, 5, pi. H , figs. 6, male ; 7, female (1892), 



