21.J. [February, 



certainly in hundreds flying about the elm trees, and resting on the flower-heads of 

 TJmbelUfercB beneath the trees ; in fact, Stephens' well known description of the 

 insect at Ripley would (except for the slaughter recorded) have well applied to 

 the present case. Since that year it has been more or less abundant at its metropolis ; 

 but what is very remarkable, it has spread during the last ten years to localities it 

 undoubtedly never occupied before, viz. : a part of Savernack Forest, south of the 

 town ; stragglers actually in the town ; and last year I am creditably informed a 

 locality west of the town. One might draw from this the conclusion, that a slow 

 migration was taking place from east to west, possibly by means of pregnant females 

 wandering by chance circumstances from the head-quarters (as the odd specimens of 

 1873 may have done), or due to circumstances concerning which we know little. 



The case of Melitcea Artemis was the converse of the above in many respects, 

 inasmuch as twenty years ago it was captured regularly in two or three localities, 

 and though local, was not, I believe, considered a rarity ; however, about the year 

 1870 the species was almost if not quite extinct, and no record of capture until 1881 

 appears in the reports of the College Nat. Hist. Soc. : for my own part I am quite 

 satisfied that if the species had occurred during those years I should have known it, 

 as I was furnished with the exact locality, and hunted for it annually, but entirely 

 without success. In 1881 it again appeared singly in widely different localities 

 (the school-field amongst others), thus strangely departing from its usual habits ; 

 for the last four years specimens have been taken in similar chance localities, and so 

 faf they do not appear to have been able to make up their minds to renew the 

 secluded habits of their ancestors. Are they to be looked upon as skirmishers from 

 an unknown head-quarters on the look out for a better billet ; are they the descend- 

 ants of some chance straggling female ; or are they obeying a law of which we 

 are ignorant ? 



Arge Galatea is first recorded in 1873 from Great Bedwyn, ten miles east of 

 Marlboro', where it occurs in abundance, and only required looking for ; it appears 

 to be following the same tactics as Thecla ui-album, a few odd specimens having been 

 taken by me in localities close to the town where they had certainly not been taken 

 before ; whether they will succeed in establishing themselves permanently in these 

 new localities is not yet evident. 



On the other hand Leucophasia sinapis, a species fifteen years ago not rare with 

 us in one or two copses, and from which I have a specimen, has now entirely died 

 out, but without apparent cause. 



The above remarks are confined to the butterflies only, but I imagine that such 

 fluctuations are equally shared by the moths, though I can give no certain data 

 regarding them. In the case of Bomhyces and NoctucB, the matter would be more 

 difiicult to investigate, and in the latter sugaring, carried out systematically for a 

 number of years would have to be done ; and this is not always practicable, and 

 includes the proverbial uncertainty of the method. Geometrce are more hopeful, 

 but I would lay stress upon the Micros giving the most satisfactory results, as many 

 species are extremely local, and the majority being of weak powers of flight, a 

 migration might be more easily noted.— N. Mandebs, Army Medical Staff, Chatham : 

 January 10th, 1886. 



