124 THE ENTOMOLOGIST’S RECORD. 
however, defined as expanding 15mm., and doubtless it also as well as 
B. veticulatella has the ‘“ cellula intrusa,’’ which M. edwardsella is 
without. Its coloration and darkening towards the hind margin dif- 
ferentiate it from M. mitfordella and associate it with M. subjlavella, 
from which it differs in size and number of antennal joints (vide, pl. 
iy., fig. 37, anterior tibia). 
The great ‘‘casta group,” with a spur length of :77-:81, is, perhaps, 
the most puzzling and difficult of all. I incline to consider them all 
as one species with a number of local races and varieties. This cer- 
tainly gets over the great difficulty of saying what many intermediate 
forms should be called. On the other hand, it is probable from the 
specimens I have examined that each colony of the species is fairly 
well-defined, and does not present, except in rare aberrations, specimens 
agreeing with other varieties, and it is evident that if this isso it must 
be largely a matter of individual predilection rather than anything else 
whether each such race is to be called a species or not. The only 
ground for doubting my conclusion to call them all one gpecies is 
that there is also some ground for believing that the wmnitidella 
and intermediella forms do occur together in some localities, and yet 
maintain themselves as separate races. This certainly requires 
further investigation. I may say that I have put names to these forms 
without sufficient certainty that I am right as to the use of the names 
mitidella and intermediella. If I am wrong this can be put right, but I 
have assumed nitidella to be the small form, which Bruand thought he 
was dealing with under the name roboricolella, but with which he 
unfortunately mixed some Proutia betulina, and. so gave an account 
which is incorrect whichever species we apply it to. 
Fumea casta.—The name casta appears to cover the great mass of 
the Fumeas in British collections, called often, with much apparent 
capriciousness, roboricolella, nitidella, intermediella, and even crassiorella 
and crassicolella. The definite character that unites all the formsis a 
length of tibial spur of from ‘77 to ‘81. The antennal joints differ from 
16 to 18 and 20, and the expanse from 9mm.tol5mm. Thereisa good 
deal of variation in wing form, generally there is a good breadth basally 
by the inner margin commencing at the base with a deep rounded lappet, 
and the inner and costal margin making some approach to parallelism. 
But not afew show a considerable approach to the form of M. mit- 
fordella. It is very possible that by measuring the spurs of a number 
of such specimens some would prove to be really MW. mitfordella. The 
several forms differ chiefly in size, but also in the number of antennal 
joints : 
a. ab. minor.—Exp. al. 9mm.-10mm., antennal joints 18, wings often more 
diaphanous than type. I have called this an aberration rather than a variety, as it 
occurs in odd specimens in different collections, and is usually probably a starveling 
form rather than a distinct race. 3 
B. var, nitidella.—Kxp. al. 1lmm.-12mm., antennal joints 18. This is a very 
definite race, and appears to be the most common and widespread form. I am by 
no means prepared to assert that this form is not a true species and distinct from 
the next form, only, if so, I cannot divide them with even approximate confidence 
(anterior tibia, pl. iv., figs. 46-47). 
y. var. intermediella.—Exp. al. 13mm.-14mm., antennal joints 18-20. This is 
rarer than the last species, and is, in places, apparently a distinct race, in others 
merely an aberration of nitidella. Some of the largest specimens have only 18 
antennal joints and some of the smallest 20, so that I feel unable to divide the 
forms nitidella and intermediella into two distinct species, defined as nitidella, 18 
