3G [J"iy. 



and Humphreys' work (vol. ii, pi. 80, fig. 10) ; Stephens says of it 

 that he has seen only two specimens, which he believes came from the 

 West of England. He might well have said farther west. It is 

 Ftycholoma melaleucana, Zeller, from Virginia, Maine, Pennsylvania, 

 and Ohio. It is well figured by Lord Walsingham (pi. 62, fig. 8), and 

 agrees with my types from Professor Fernald. 



" Flavofasciana.'" — This moth is figured under the same name by 

 Humphreys (W. and H., vol. ii, pi. 99, fig. 16), with the statement — 

 "from Mr. Stone's collection, now in the cabinet of Mr. Beutley." 

 From Mr. Beutley's cabinet it passed to Mr. E. Shepherd's. It is 

 Sericorls instrutana, Clemens, from North America, and agrees with 

 types from Prof. Fernald, sent as Exartema fasciatana. 



King's Lynn, Norfolk : 

 March, 1887. 



THE PROBABLE MIGRATION OP AFORIA CRATMGI. 

 BY J. W. TUTT, r.E.S. 



I should like to say a few words with regard to the note of 

 Mr. Goss, published in the Ent. Mo. Mag. (vol. xxiii, p. 220-221). Mr. 

 Goss, in his first paragraph (on p. 257), shows that he does not exactly 

 grasp the meaning I intended to convey, when he says, " By this I un- 

 derstand Mr. Tutt to mean that the same conditions of the climate of 

 this country, which have been unfavourable to the development and 

 increase of indigenous specimens of this species, and have tended 

 towards its rarity or extinction, have also prevented its recruiting its 

 numbers by migration, or rather immigration, from the Continent." 



This sentence certainly does not exactly embody the view I hold 

 on the subject. Facts prove that we have at various times had Aporia 

 crataegi very abundant in England (sometimes for many successive 

 years), and at other times it has been exceptionally scarce. Mr. 

 Baker's letter (p. 256) shows one such case, my own letter (pp. 220, 

 221) gives another. 



I believe that certain species of Lepidoptera, among them pro- 

 bably A. crataegi, are migratory in their habits, and that migration or 

 immigration takes place at no fixed time or period, but is totally de- 

 pendent on certain general* causes, atmospheric or otherwise, about 

 which we are all (as far as I know) in the most perfect ignorance, and 

 may take place in several successive seasons, or may not take place 



* I have used the word "general," because the causes which induce migration here are appa- 

 rently at work in other parts of the world— Arcerica, Ceylon, &c. 



