202 Mr. A. G. Butler on Lepidoptera 



Salanga ; 28. /, pallida, of Upper Tenasserim ; 29. /. citrina, 

 of Upper Tenasserim ; 30. /. andamana, of the Andamans ; 

 31. i., sp.?, of the Thoungyeen Valley, Tenasserim; 32. /. 

 mariannm, of the N.W. Himalayas, Bombay, Ceylon, &c. ; 

 33. I. meridionalis^ of Poona and Bombay ; 34. 7. agnivernay 

 of Poona and Bombay ; 35. /. depalpura, of Depalpm*, &c. 



Probably no collections but our own and Mr. Moore's are 

 sufficiently rich in the various closely-allied types of Ixias to 

 show the perfect gradation which exists in the above series, 

 and, consequently, to many lepidopterists the differences upon 

 which some of them are separated must appear to be trivial in 

 the extreme ; nevertheless, I am convinced, after examining 

 the numerous collections which have come to hand during the 

 last twenty-three years, that most of the above are strictly 

 constant to locality, and that only such species as have a wide 

 geographical range (as /. evippe) show any tendency to vari- 

 ability {i. e. individual inconstancy), and even then that there 

 is never any difficulty in deciding to which Ixias the aberrant 

 specimen belongs. 



In a case like the foregoing, and it is not a solitary one by 

 any means amongst the Lepidoptera, only two courses are 

 open to the system atist : he must either say that the genus 

 consists of one species exhibiting local modifications, the 

 degrees of which are trivial, but the sum of which, comparing 

 the first and last, is prodigious, or he must separate all the 

 forms as species, no matter whether their modification has 

 been due to isolation on islands, by mountain ranges, by 

 rivers, or limitation of food-plant. 



84 . Catopsilia jugurthina. 

 Colias jugurthina, Godart, Enc. Meth. ix. p. 96. u. 21 (1819). 



(J . Hassan Abdal, 27th June ; Chuttar, between Tret and 

 Barracoo, Murree road, 9th October; $. Hurripur, 14th 

 October, 1886. 



This is one of the forms of the C. crocale group, of which 

 at present we know too little to be certain whether it is con- 

 stant or otherwise ; it is certainly the commonest of the Indian 

 forms, and its range is enormous, extending along the base of 

 the Himalayas and down the east of India to the Malayan 

 Islands, certainly as far as Waigiou, with scarcely any altera- 

 tion of pattern. The locality of C. crocale is said to be " East 

 Indies ; " in the Museum collection we have it (I speak of 

 the typical form) from Ceylon and Malacca only. In my 

 opinion it is highly probable that the latter is an aberrant 

 development of the same species, tending to resemble the 



