British species of Scoparia. 503 
weakening the little he said about w/mella. Barrett, later 
(1904), followed Knaggs, and Spuler (1910) followed 
Staudinger. 
An examination of the genitalia confirms the conclusion 
arrived at by Bankes, Bower, etc., and shows the high 
authorities above quoted to be in error. 
The British Scoparias appear to divide themselves 
into two groups. Bionomically these are (1) those whose 
larvae are more or less known to feed on mosses and 
lichens; (2) those whose larvae are for the most part 
unknown, but probably, from the analogy of S. cembrae, 
the only one of the group certainly known, feed on the 
root stocks of flowering plants, and most likely of com- 
positae. These two groups may also be defined by the 
male appendages, the latter group possess very large and 
obvious darts (cornuti) on the eversible membrane (vesica, 
Pierce) of the wedoecagus, the former (the moss-feeders) are 
quite without them. That they possess other obvious 
characters to distinguish them is proved by the fact that 
nearly all accounts of the genus place the root-feeders 
(if so) together, at the beginning, with the moss-feeders 
following, or vice-versa. 
The British species that belong to the root-feeders are— 
cembrae. 
basistrigalis. 
ambigualis (atomalis). 
ulmella. 
dubitalis (ingratella). 
The remaining nine are the moss-feeders. 
The root-feeders may be defined— 
Ist. As root-feeders. This is a definition founded not 
on knowledge, but on ignorance, and so may seem open to 
objection and even ridicule. It takes, however, a positive 
and unobjectionable form, if we say, had they been moss- 
feeders we should have ascertained it, therefore they must 
feed on something else ; that that something else is roots is, 
of course, a guess founded on our knowledge of one (or 
possibly two) species only. 
2nd. There is a decided difference in wing form. The 
ends of the fore-wings are more square in the root-feeders, 
more oblique, 7.e. with more pointed apex in the moss- 
feeders. There is a little corresponding difference in 
neuration. In the moss-feeders the portion of cell margin 
between veins 3 and 4 of the fore-wing is shorter, and 
LL 2 
