56 Dr. A. G. Butler on the Old- World 



A Revision of the Pierine Butterflies of the, Genus Terias 

 from the Old World. By ARTHUR G. BUTLER, Ph.D., 

 F.L.S., F.Z.S., &c., Senior Assistant- Keeper, Zoological 

 Department, British Museum. 



THE genus Terias has always been a puzzle to Lepidopterists 

 and probably will never be thoroughly understood until the 

 whole of the species have been reared from the egg through- 

 out the year and in all parts of the world where they exist. 

 At the same time, the careful labelling and dating of col- 

 lections in recent years and the study which has been 

 devoted to this genus in India and Africa have thrown 

 considerable light upon the relationship of the numerous 

 forms which, even in my "Notes on the Genus Terias " (Ann. 

 & Mag. Nat. Hist. ser. 5, vol. xvii. pp. 212-225), I was 

 obliged to regard, for want of evidence to the contrary, as 

 distinct species. 



The researches of Capt. E. Y. Watson, C. W. Barker, and 

 G. A. K. Marshall have conclusively proved that many of 

 the supposed species of the genus are either seasonal or 

 varietal : the wet-season forms having the under surface of 

 the wings white or yellow, usually with somewhat feeble 

 markings, or even none at all; the dry-season forms either 

 reddish in colour, sometimes with ill-defined markings, or 



