136 Dr. A. G. Butler A Revision 



Group 3. (Type /. pyrene.) 



This is the largest and most perplexing group in the genus, 

 and it is possible that I may not have sufficiently reduced the 

 number of named species ; this, however, is, I think, prefer- 

 able to reckless sinking of forms which are locally constant 

 under one heading. In the late Capt. E. Y. Watson's 

 review of the Indian species it is difficult to comprehend his 

 meaning ; he regards the whole of the species of the present 

 group as one ; but he says : " /. pyrene is very subject to 

 both climatic and seasonal variation, and many forms have 

 been named. Of these some are fairly distinct, and the males 

 can be compared as below " 



Now it seems to me that to discriminate between " a distinct 

 climatic form " and " a species " we must have a universally 

 accepted definition of what a species is, which is impossible : 

 therefore, to my mind, if a thing is distinct it ought not to 

 receive the same name as that from which it is admitted to 

 be distinct, for to give the same name to two distinct things 

 is to stultify the very object aimed at in nomenclature. 



In the present group the wet-season forms are usually 

 almost unmarked below and the dry forms heavily speckled 

 and ocellated, whilst the outer borders on the upper surface 

 are, as a rule, considerably broader in the wet than in the 

 dry forms, sometimes disappearing entirely from the second- 

 aries of the latter. 



10. Ixias rhexia. 



rf . Papilio rhexia, Fabricius, Syst. Ent. p. 476 (1775) ; $ . Butler, 



Cat. Fabr. p. 216, pi. i. fig. 5 (1870). 

 $ . Papilio pirithous, Fabricius, t. c. p. 483 (1775). 

 2 Ixias familiaris, Butler, Trans. Ent. Soc. 1874, p. 432. 



Ranges from Tibet through N.E. India into Burmah. 

 Twenty-nine examples. B. JV1. 



There are five examples in the Hewitson collection, one of 

 which is a remarkable albino male, having a white instead of 

 orange patch on the upper surface of the primaries. 



11. Ixias evippe. 



Papilio evippe, Drury, 111. Exot. Ent. i. pi. v. fig. 2 (1773). 

 Ixias anexibia, Hiibner, Verz. bek. Scnmett. p. 95 (1816). 



S.E. China and the Island of Hainan. B. M. 



The Museum series consists of thirteen examples, and 

 there is one specimen in the Hewitson collection. /. anexibia 

 is the dry form and /. evippe the wet. 



This and the preceding species have long been confounded, 



