NYMPIIALID.E. NYMPIIALIN.E. CYRESTIS. 251 



R First subcostal nervule only of forewing emitted before the end of the cell. 



a. Both wings on upperside with eight straight, clearly-marked black lines. 



549. C. (Chersonesia) risa, Kumaon, Sikkim, Assam, Chittagong, Upper 



Tenasserim, Java. 



b. Both wings on upperside with seven black lines only, the fifth from the base replaced by a diffused 



blackish fascia, the two lines beyond much curved and uneven. 



550. C. {Ckersonesia) rahria, Upper Tenasserim, Malayana. 



544. Cyrestis thyodamas, Boisduvai. 



Cyresihthyodamas, Boisduvai, Cuvier's Regne Animal, Insectes vol. ii, pi. cxxxviii, fig. 4(1836); id.. Double, 

 day, Hewitson, Gen. Diurn. Lep., vol. ii, p. 261, n 4, pi. xxxii, flg. 3 (1850); id., Butler, Ann. and Mag. of Nat. 

 Hist., fifth series, vol. xvi, p. 307, n. 55 (1885) ; C. thyodamas, var. andaiizanica. Wood-Mason and de Nioeville, 

 Journ. A. S. B., vol. 1, pt. 2, p. 246, n. 31 (1881) ; Amathiisia ffanescha,Vio\\a.x, Hiigel's Kaschmir, vol. iv, 

 pt. 2, p. 430, n, i, pi. vii, figs. 3, 4 (1848) ; Cyrestis ganesclia, Butler, Ann. and Mag. of Nat. Hist., fifth series, 

 vol. xvi, p. 308, n. 56 (1885). 



Habitat : Himalayas, Assam, Kliasi Hills, Cachar, Upper Tenasserim, Andaman Isles, 

 Bombay, South India. 



Expanse : 2*2 to 2"8 inches. 



Description : Male and female. Upperside, both wings of different shades, varying 

 from pure white to rich ochreous. Forewing with the costal area especially basally more ot 

 less infuscated, crossed by numerous fine black lines : — first a longitudinal one at the base of 

 the cell, second an oblique one across the cell from the costa to the median nervure, the third 

 crossing the cell obliquely continued to the submedian nervure of the hindwing, the fourth 

 outwardly much arched confined to the cell, the fifth and sixth enclosing the disco-cellulars, the 

 seventh, eight and ninth discal, continued across the hindwing, the eighth with a blackish 

 smudge placed inwardly against it on the costa, and often with a more or less distinct diffused 

 powdery black rounded spot beyond it in the lower discoidal interspace, the ninth the most 

 prominent of all, marked with steel-blue from the second median nervule of the forewing to 

 the anal angle of the hindwing, followed by an irregular series of annular ochreous spots more 

 or less obsolescent in the middle of the wing, most prominent at the inner angle where they are 

 richer coloured ; the margin marked with four more fine black lines, the three outer ones placed 

 upon a more or less decreasing fuscous ground. Hindwing with the disco-cellulars marked 

 with a fine black line, the tail black tipped and irrorated with white, the anal lobe and anal 

 angle marbled with numerous irregular ferruginous, steel-blue and white spots, the abdominal 

 margin more or less powdered with black. Underside paler, marked much as above, the 

 terruginous markings at the anal angle and lobe of the hindwing more distinct, the latter with 

 a prominent black spot in the middle. 



Mr. Butler (1. c.) writing of this species says that it ' ' has long been confounded with the 

 following [C. ganeschd], which, if not distinct, must surely, I think, be a seasonal form ; it 

 has probably been assumed (without examination) to be the female of C. ihyoda/nas." He 

 keeps (1. c.) C. ganescha as a distinct species, and adds this note :— " This is a yellow insect, 

 with most of the markings on the wings of a deeper yellow, a few only remaining black ; 

 the apical area is not smoky brownish, as in C. thyodamas. If it be a seasonal form of the 

 preceding [C. thyodamas\ one form must have been just disappearing as the other emerged 

 from pupa, for in no other way can one account for both of them having been taken at about 

 the same time." It is not clear on what grounds Mr. Butler says that the typical C. ganescha 

 is a yellow insect ; Kollar in two places describes it as white. The smoky brownish apical area 

 of the forewing is exceedingly variable, and there appears to me to be no grounds whatever 

 for dividing this species into two. The yellow specimens are usually females in the Western 

 Himalayas, but in Sikkim they are quite as often males, this dark colouration may be due 

 to reversion to an ochreous ancestor, and it varies much in intensity in different specimens, 

 every gradation being found between the whitest and the yellowest specimens. This yellow 

 form does not appear to occur in South India. C. thyodamas is usually a common species 

 where met with, but Mr, E. H. Aitken informs me that it is rare at Mahableshwar ; it occurs 



