A EEVISION OF THE OEIENTAL HESPERIID^. 175 



most remarkable feature of the genus is the frenulum-like tuft of bristly hairs found at 

 the base of the costa of the hind wing in the male. 



The following table deals only with the three species in coll. Elwes : — 



Males. 



1 (4). Fore wing with a red band, at least on the underside. 



2 (3). Red band on fore wing below broader, its breadth near the 



middle about equal to one-third of the length of the costa . xanites, Butl. 



3 (2) . Red band on fore wing below narrower, its breadth near the 



middle about equal to one-fourth of the length of the costa. hector, Wats. 

 4(1). Fore wing without any red band iw/Zeri, W.-M. & de Nicev. 



With regard to E. xanites and K. hector, it is difficult to lay down any satisfactory 

 character for the separation of these two species, if species they are. In their typical 

 state they offer no difficulty, K. xanites being the larger insect, expanding about 

 41 mm., with the red band on the fore wing above broad, and reaching from the middle 

 of the costa to the tornus; whilst E. hector is smaller, expanding about 35 mm., with 

 the red hand on the fore wing above comparatively narrower and rarely reaching quite 

 to the tornus, frequently abbreviated at each end, and sometimes entirely wanting. 

 Pending the comparison of the male genitalia of typical specimens when opportunity 

 offers, we find that the most constant character by which to separate the two forms lies 

 in the relative breadth of the red band of the fore wing, as exhibited on the underside. 



! KOKUTHAIALOS XANITES. 



Astictopterus xanites, Butler, Trans. Ent. Soc. Lond. 1870, p. 510 ; id. Trans. Linn. Zool. Soc. ser. 3, 



voL i. p. 555, pi. kix. fig. 7 (1877). 

 Koruthaialos xanites, Watson, P. Z. S. 1893, p. 77. 



Hah. Borneo {fide Butler); Malacca '{fide Watson); Kina Balu, Borneo {Water- 

 stradt) ; Perak, Bali {JDoherty). 



! KOKUTHAIALOS HECTOR. 



Koruthaialos hector, Watson, P. Z. S. 1893, p. 77. 



Astictopterus xanites. Distant, Rhop. Mai. p. 402, pi. xsxiv. fig. 38 (1886) ; Watson, Hesp. Ind. 



p. 145 (1891). 

 Astictopterus xanites, var. palawites, Staudinger, Iris, ii. p. 148 (1889). 

 Keraiia gemmifer. Semper, Schmett. PhiUipp. p. 318 (1892), sec. spec. comm. 



Hob. Luzon {fide Semper) ; Palawan {fide Staudinger) ; Burmah {Adamson, Doherty) ; 

 Tenasserim {Bingham) ; Perak, Pulo Laut, Bali, Arjuno, Java {Doherty) ; Java {Piepers) ; 

 Bunguran, Natuna Is. {Everett) ; Palawan {in coll. Eothschild). 



! KOKUTHAIALOS BtTTLEKI. 



Astictopterus butleri, Wood-Mason & de Niceville, Jour. As. Soc. Beng. 1883, p. 98, pi. x. 

 fig. 3, d; iid. op. cit. 1886, p. 380. 



2a2 



