Mr. A. G. Butler on Madagascar Lepidoptera. 337 



;wo blue-centred anal spots in the secondaries, and the body- 

 above black ; wings below snow-white, with brown-edged 

 markings similar in form and position to those in G. Poggei 

 (Dewitz in Nova Acta Acad. Leop.-Carol. Nat. Scr. p. 33, 

 pi. xxvi. fig. 7), but not filled in with black as in that species. 

 Expanse of wings 1 inch 1 line. 



This species may be readily distinguished from the West- 

 African G. Poggei by the metallic golden coloration of the 

 upper surface, and the slenderness and length of the interner- 

 vular black streaks, in which last character it agrees with G. 

 juba$ , Fabr. (Plebeius Falkensteinii, Dewitz), figured in my 

 Fabrician Catalogue, pi. ii. fig. 9. ■ 



18. Castalius leucon. 



Lyccena leucon, Mabille in litt. 



This species having only at present appeared in an adver- 

 tisement-sheet (Pet. Nouv. ii. p. 289, 1879), I cannot regard 

 it as a published species ; it may, however, be the female of 

 my Castalius azureus, from which it differs on the under 

 surface in the absence of the discal series of black spots on 

 the primaries. 



Papilionidae. 



PiERmm. 



19. Nycliitona sylvicola. 

 Leucophasia sylvicola, Boisduval, Faun. Madag. p. 20 (1833). 



The black apical patch is strongly marked in this example 

 precisely as in our N. medusa. 



The pure white species is apparently referable to N. 

 nupta. 



20. Terias aliena, sp. n. 



Above bright sulphur-yellow, paler upon external border ; 

 primaries with a pale brown regular apical border : secondaries 

 subangulated. Wings below uniform sulphur-yellow : prima- 

 ries with a squamose dark brown dot in the cell ; two dots 

 on the discocellulars, a large quadrate apical patch, and the 

 greater part of the outer margin pale orange : secondaries 

 with two widely separated dots near the base, two lunate 

 markings below the first and second median branches, and 

 two small annular markings on the discocellulars brown ; a 

 subcostal dash, a broad oblique subapical streak, and a lunate 

 marking on the second median interspace orange ; veins 

 terminating in extremely minute black points ; fringe saffron- 

 yellow. Expanse of wings 1 inch 5 lines. 



