804 THE ENTOMOLOGIST. 
grass-feeder.—WinLiAM Macuin; 29, Carlton Road, Carlton 
Square, E., November 5, 1886. 
PsYCHE OPACELLA AT Rannocu.—I got in Rannoch, this 
season, a specimen of Psyche opacella, in good condition. Is it 
not rather a rarity, and generally found in the New Forest? I 
never met with it before in Rannoch. I also took Stilbia anomala 
there —for the first time since 1868 or 69. — EL1zaABETH Cross; 
The Vicarage, Appleby, Doncaster, October 19, 1886. 
ProcHEvuusA (GELECHIA) SUBOCELLEA FEEDING ON T'HYME.— 
I have received from Mr. J. H. Wood, of Tarrington, Ptocheuusa 
(Gelechia) subocellea cases infested by a Chalcid, with a remark, 
“The cases were abundant on wild thyme, but the great majority 
stung.” The larve attacked are only about half-grown, conse- 
quently the larva-cases are small, but, notwithstanding, they are 
very conspicuous on the withered flowering stems. The end of 
the case, from which the larva protruded its head, is affixed to 
the calyx of the seed-pod from which it made its last meal. I do 
not remember seeing it mentioned before that P. swbocellea fed on 
the seeds of the thyme as well as marjorum.—G. C. BIGNELL; 
Stonehouse, Plymouth, October 9, 1886. 
WuatT consTITUTES A Species ?—I should like to be allowed 
to say a few words with regard to Mr. South’s statement as to 
what constitutes a species. I don’t think entomologists are so 
much at a deadlock as he seems to think, with regard to their 
ideas of what constitutes a species (Entom. 270); and the im- 
portant factor to me seems to be, will the individual copulate 
freely in a state of nature, to propagate their own particular 
kind? If so, however variable the forms may be, I think it is 
generally recognised that the progeny form but one species ; and 
I believe I am quite safe in saying that this is the chief point in 
the minds of most entomologists. If this be so, I must ask Mr. 
South one question. Has he or any careful observer ever seen 
an undoubted specimen of the early brood which we call crepus- 
cularia in copulation with an undoubted specimen of the late 
brood which we call biuwndularia? Only this year we had a 
notice chronicled in the ‘Entomologist’ of their occurrence at 
the same time. I have noticed the same thing myself, but I 
never saw copulation take place, and as we get some strange 
cases of unnatural copulation noticed at times, it seems strange 
