726 MR. A. G. BUTLER ON A NEW GENUS OF LEPIDOPTERA. [Dec. 5, 



such genera as Appias and Belenois of the Pierince, in consequence 

 of the fact that their structural distinctions are confined to the 

 male sex. 



At page 395 of the • Genera of Diurnal Lepidoptera,' in a foot- 

 note, Prof. Westwood characterized the typical species of this new 

 genus under the name of Apatura osteria, the type being in the 

 collection of the British Museum ; as it was at that time the only 

 example we possessed, and was destitute of an abdomen, no notice 

 was taken in the diagnosis of the form of its anal valves ; and conse- 

 quently the species has remained without molestation in the genus 

 Apatura up to the present time. 



In the year 18G8 a pair of A. osteria, in fair condition, were 

 presented to the Museum by R. B. Were, Esq., who took them in 

 India ; in 1869 a male in good order was obtained from a collection 

 made in Sarawak by Mr. Lowe ; and last year Lieut. Henry Roberts 

 presented a fine pair taken by himself at Singapore. 



The female of A. osteria is of an olive-brown colour above, the 

 primaries with a macular angulated white band, which becomes 

 obscured by olive-brown in the secondaries ; the discal area beyond 

 this band is semihyaline and whitish in the primaries, and is fol- 

 lowed by two obliquely placed subapical white spots and a sub- 

 marginal series of whitish lunules ; there is also a white-zoned blind 

 ocellus between the first and second median branches ; the discal area 

 of the secondaries is ochreous brown, crossed by a darker brown 

 macular bar, and followed by a series of broad white-zoned brown 

 spots, bounded externally by brown, the margin pale brown ; a 

 black blind ocellus between the first and second median branches. In 

 the shape of the wings and the colouring of the male this Butterfly 

 reminds one of the smaller African species of the genus Charaxes ; 

 the hind wings, however, possess no trace of the tails so common 

 in that genus. 



Eulaceura, gen. nov. 



Nearly allied to Apatura, but differing in its comparatively longer 

 and more graceful anterior, and its shorter and more rounded pos- 

 terior wings ; antennae longer, more slender, the club somewhat 

 compressed laterally ; median nervure of posterior wings longer, and 

 consequently second and third median branches shorter. 



Abdomen of male with anal valves composed of an upper hood- 

 like lip, fringed externally with short hair-scales, and sheathing the 

 penis, which is shorter and more spine-shaped than in Apatura, and 

 projects obliquely downwards between two bispinose lateral walls of 

 horny texture, and in shape resembling the open beak of a bird ; 

 the lower lip is formed by the union of two closely fitting horny 

 sheaths, deeply excavated within, and terminating abruptly in two 

 strong, perpendicular, somewhat curved, tapering, horny hooks, 

 about a line and a half in length. 



Typical species Eulaceura osteria, Westwood. 



