266 THE ENTOMOLOGIST. 
examples of each, whitish patch. Some examples of radiatella 
have a dark streak running through the wing from base to apex; 
this streak is always more or less distinct as far as the middle of 
the wing in costella, and forms a border to the costal patch. In 
one example the streak is to be traced right through to the apex. 
Another feature common to both insects, but perhaps most 
constant in costella, is a short blackish dash from the base to the 
inner margin. Of dark radiatella the head and thorax are of the 
same colour, but specimens ornamented with white have the head 
or thorax, sometimes both, also white, or marbled with white. 
The head and thorax of costella are invariably white or pale 
ochreous. ‘There is no appreciable difference in the hind wings 
of the two insects. As far as I know the larva of each feeds in 
May and June on oak. 
As many Maicro-lepidopterists have probably bred these 
insects, it would be interesting to have their experience. 
Possibly the larva of one of these insects may possess some 
trustworthy character which will serve to separate it from the 
other more readily than seems possible in the perfect state. Of 
course in a rough-and-ready way the insects are easy enough to 
Separate, but such a division seems hardly satisfactory. What 
we want to know is this,—Are Cerostoma radiatella and C. costella, 
as they now stand, really two good and distinct species? If the 
insects are specifically distinct, do forms of the one so closely 
resemble forms of the other that the species to which each 
should be referred is difficult to determine ? 
12, Abbey Gardens, St. John’s Wood, N.W. 
THE LIFE-HISTORY OF THEPHROSIA CREPUSCULARIA 
(OR BIUNDULARIA). 
By tHE Rey. G. A. SMaLuwoop. 
As the wish has been repeatedly expressed that the egg and 
larva of this insect should be accurately described, and as I have 
bred it for some years, I will now supplement my former papers 
(Entom. 161, 181) by giving some notes on the life-history of the 
species, which, although styled biwndularia by myself and others 
(for the sake of clearness merely) in the recent discussion, is the 
