252 Dr. Frederick A. Dixey on the 
by the arrangement at present adopted in the National 
Collection under his charge. I confess that { am not 
always in agreement with this arrangement, but the 
importance of a definite and accessible standard is obvious, 
and no better one could be found for my purpose. Hven 
if the genera are not in every instance distinguished by 
characters of real ‘‘ generic value,” they are usually 
natural groups, and in most cases of great convenience in 
practice. The list of genera and species which I have 
appended may be found useful as indicating the exact 
insects which are mentioned in the course of the paper, 
and also as giving an idea of the scope and contents of 
those genera whose names may still be somewhat un- 
familiar. A paper of this kind is not the place in which 
to introduce changes of nomenclature or to discuss 
questions of synonymy ; and as regards classification I 
have done no more than throw out a few suggestions 
which, perhaps, may one day be taken up. 
II. Tae WinG-MARKINGS. 
1, The submarginal series of dark spots. 
Comparing together the three species of the subfamily 
Pierine that are commonest in this country, viz., Ganoris 
brassice, G. rapx, and G. napi, we find that the females 
of all three resemble one another in the possession of a 
series of black spots on the upper surface of the forewing. 
One of these spots (Fig. 16, 8 8) occurs between the 
second and third median nervules ; another (ibid., S 10), 
between the first median nervule and the submedian 
nervure ; and the third (ibid., S 11) between the 
submedian nervure and the inner margin of the wing. 
The latter spot, which varies considerably in the amount 
of its development, takes the form of a streak nearly 
parallel with the inner margin. In the males, this series 
of spots is evanescent. The whole series is normally 
absent in G. brassice ¢, and in some specimens of 
G. rapes, and G. napi 3; the males of the two latter 
species, however, generally have the spot between the 
second and third median nervule more or less developed, 
though the other two are not present. Turning to the 
underside of the wing in these species, we find the first 
two spots usually present in both males and females; 
