CATAL0GT7E OF BFTTERPLIES. 19 



and called it the " White Petticoats." That this is appro- 

 priate no one will dispute, and its use certainly implies that 

 the insect occurred with sufficient frequency to have acquired 

 a popular name. My own opinion is that a much larger number 

 of Butterflies existed in Britain at a former period than have 

 been found within the last half century. Comparing other 

 groups of European Lepidoptera, as given in Dr. Staudinger's 

 Catalogue, I find that only about half the proportion of Rhopa- 

 locera occur as of other groups, I therefore think it likely 

 enough that Antiopa was at one time or another a species that 

 might be regularly met with in Britain, and may then have pro- 

 pagated its race within the limits of these islands. But that is 

 certainly not so at present. Much more is known now respect- 

 ing the migration of insects. An American Butterfly, Anosia 

 plexippus, has undoubtedly crossed the Atlantic and reached our 

 shores, not once or singly, but several times, and twice in some 

 numbers. There is therefore no great difficulty in understanding 

 how Antiopa may cross the comparatively narrow !N^orth Sea. 

 The late Mr. H. T. Stainton, whose knowledge and judgment 

 in such matters were second to none, was of opinion that the 

 larger swarms of Antiopa, which had been noticed in Britain, 

 had a Scandinavian origin, the white-bordered form being found 

 there. The cream-bordered specimens more frequently occurring 

 singly in the south, probably cross from the French coast, where 

 the insect is common. 



Though Mr. Wailes appears to have held the opinion that 

 Antiopa was reared within these counties, he was able to give 

 but few instances of its occurrence, and those only singly. He 

 quotes two records of its appearance in the south-eastern corner 

 of Durham, besides those seen by Mr. Backhouse ; — one on 7th 

 August, 1831, and another on 2nd September, 1842, when Mr. 

 Hogg saw the first, and captured the second specimen. The 

 other records in his list are, '' once near Gibside. Mr. J. Han- 

 cock." " One seen near Twizell some years ago. P. J. Selby, 

 Esq." ''■ A specimen at Longhirst about the middle of August, 

 1857. Ent. W. Intelligencer II., 182." 



Later records are " one seen by keeper at Castle Eden Dene," 



