British species of Scoparia. 505 
By this 38rd character pallida is a moss-feeder. It is 
the only British species that is not by these 2nd and 3rd 
set of characters distinctly of one group or the other. 
There is a difference in the ? genitalia in at least one 
point between Scoparia (root-feeders) and Hudoria (moss- 
feeders. In Hudoria there is a small area quite entitled 
to be called the lamina dentata, as here the angular chi- 
tinous points are packed closely together and are well 
developed, being over the rest of the sac hardly present. 
In Scoparia they are very little more developed at one 
point than another, but more developed than they are in 
the unspecialised area in Hudoria. Still, there are several 
species that do not show this difference in at all a marked 
manner. 
I present photographs of the terminal segments of the 
females of most of the species dealt with, and also of the 
Bursae. 
I cannot define the genera on characters from these 
structures, perhaps because I have not studied them 
enough. There is a tendency, however, in the moss-feeders 
to agree in having a somewhat spherical bursa, with a 
patch of spicules, and to have a structureless spherical 
cavity beyond the bursa. In the root-feeders the tendency 
is to have this tract less markedly divided into spherical 
cavities; the bursa is a widened portion of the tube, with 
spicules well distributed, but more developed on either 
side, and there may be a not dissimilarly armed area nearer 
the lower end of the tube, whilst the upper unarmed 
termination is not separated from the bursa by a very 
marked constriction. But individual species are sufficiently 
exceptional to prevent any definite rule appearing. It is 
also certainly the case that the last segments, by their form 
and the length of the rods, show much greater extensibility 
in the moss-feeders than in the root-feeders, implying that 
the former place their eggs more deeply than the latter do. 
There is another character that is very variable between 
the different species in the relations of veins 7 and 8 of 
the hind-wings. The anastomosis of these obtains in so 
many genera of Pyrales, that one hardly expects it to be 
so very variable in amount in one genus. In basistrigalis 
they do not really anastomose, but only touch for about 
03mm. In alpina they are coincident for about 1 mm., 
but I do not find that this difference obtains in a way to 
distinguish the moss-feeders from the root-feeders, since it 
