1900.] 29 



All that I caught were also males. Mr. Bonaparte Wyse had a similar 

 experience in other parts of this county (" Irish Naturalist," 1899, 

 p. 228), and at Passage West, Co. Cork. 



It is difBcult to account for such a sudden increase, and I think 

 more difficult to understand why the butterflies that three observers 

 noted should have all been males. 



If the butterflies that Mr. Cruttwell and others observed in such 

 unusual numbers reached our shores by migration, where did they 

 come from ? 



My own idea is that Colias Edusa owed its presence in the Co. 

 Galway, and in other parts of Ireland, not to migration, but to some 

 climatic conditions or exceptional circumstances that favoured its 

 rapid increase last year. An exceedingly dry and warm summer, like 

 that of 1899, a probable absence of insect and other enemies, and the 

 fact that other parts of the county might not have afforded such a 

 good feeding ground as the place where Mr. Cruttwell observed them — 

 these things might have caused them to congregate in such numbers 

 in that particular locality. Colias Edusa is exceedingly powerful on 

 the wing, and is therefore able to change its quarters very readily. 

 That strip of flowery meadow (mentioned by Mr. Cruttwell) must 

 have proved an irresistible attraction, and a haven of rest to every 

 passing Edusa. But why all should have been knights errant seems 

 to me quite iuexplicable. 



Coolfin, Portlaw, Co. Waterford : 

 January, I99O. 



ON A NEW FORM OF AGRIAS SARDANAPALUS, Bates. 

 BY PERCY T. LATHY. 



Ageias Sarda-Napalus, Bates, ab. Hades (ah. nov.). 



Differs from ab. lur/ens, Stgr., in the total absence of blue on the 

 hind-wings. 



Hub. : Chanchamayo. In coll. H. J. Adams. 



A single specimen of this interesting form was obtained, together 

 with typical Jitgens, from a large collection from Chanchamayo in 

 Peru. Dr. Staudinger, in his Eevision of the genus Agrias, Iris, 

 Band xi, Heft 2, fig., p. 363, says of his ab. lugens, that the blue is never 

 entirely absent from the hind-wing. Another specimen from the 

 same parcel closely approaches this form, the blue patch being only 

 represented by a few scales. 



Lynton Villa, Sydney Road, Enfield : 

 January, 1900. 



