516 Dr_T. A. Chapman on the 
top of the opening, like two pillars, instead of gradually 
widening from a pointed end, and the top is nearer a 
transverse straight line than an arch. 
Truncicolella (figs. 47-49) differs from frequentella and the 
rest of this group in the width of the aedoeagus (0°20 mm.). 
It also differs from /requentella in the base of the tenth 
sternite sloping up to the shaft, and in the shaft itself 
being therefore proportionately shorter, and in that it 
is tapering instead of rod-like, being thicker at its base. 
The opening of the “slipper” is much as in /requentella, 
but in ¢rwneicolella one sees that these differences in the 
opening of the slipper are merely apparent ; what differs 
is that the “upper” of the “slipper” is in mercwredla 
of uniform texture, in ¢runcicolella the medium strip 
from the opening to the tip is comparatively pale and 
structureless, and probably in sudetica is still present, but 
more membranous and invisible. 
The appendages of sudetica and petrophila seem to be 
identical. There is a trifling difference in size. The length 
of clasp of four petrophila averages 1:1 mm., of ten sudetica 
1:04. Except that petrophila is much darker in colour, I can 
see no difference in the general character of the imagines. 
I think, therefore, these two are local races of one species. 
Sudetica is a very variable insect both in size and depth of 
colour, and I imagine if the depth of colour in any locality 
exceeds a certain amount it 1s called petrophila, 
EXPLANATION OF PLATES. 
All figures x 20 except figs. 23, 27, 30, 46, 67, 68, 69, 70, 72 and 
74, which are x 40, and 71 x 30. 
PLATE XXXV. Fie. 1. Cholius ochrealis, 6. 
2. Scoparona centuriella, g lateral view. 
” ’ d- 
s re , @ bursa. 
= - , @ last segments. 
4 
5. 
PuaTE XXXVI. Fic. 6. Scoparia dubitalis, ¢. 
7 
8 
9 
oe 
5 ingratella, ¢. 
* ambigqualis, @. 
3 dubitalis, 2 last segments and 
bursa. 
ambigualis, ¢ lateral view. 
iUle Re atomalis, 2. 
