514 Dr. T,A. Chapman on the 
a 
the sections in having a dense margin above and below, 
and always tending to fold in the intermediate softer 
portion, so as to be very troublesome to spread, in a way 
different from either of the other sets. 
This very distinctive structure of the appendages shows 
that it is wholly unrelated to /requentella (mercurella). 
In the moss-feeders there is difficulty in finding any 
striking characters to distinguish the several species, such 
as are afforded by the cornuti of the root-feeders. There 
are, before going into specific detail, to be noted two 
structures (or parts of one) that are present in all these, 
but one of which is apparently wanting in the root-feeders, 
or if present is in a rudimentary and inconspicuous 
condition. ‘These would appear to be details of the penis- 
sheath, 7.¢. of the floor of the cavity in the region where 
the aedoeagus pierces it. One is a thin flat plate of 
chitin, of somewhat pear-shaped outline, the rounded end 
attached between the bases of the clasps and the narrow 
end close to the aedoeagus and with the rest of the floor 
attached to it, and is dragged when the aedoeagus is 
forcibly displaced. (This can be seen in the root-feeders. ) 
The other consists of two small rounded eminences, one in 
either side, carrying a few hairs. 
As arule, both insects and appendages are smaller than 
in Scoparia. 
Pallida (figs. 36-38, 67) has the tenth sternite broad and 
flat, hardly divided into an arch at base, and a long narrow 
body. The neck is half-way up, the body is comparatively 
broad, so that it is more nearly a flat triangle than the 
arch below and the rod-like body above, as in most species. 
Alpina (fig. 57) may be distinguished from the other 
species under review by the character of the tenth sternite, 
which has spreading wings forming the arch, but the 
column is broad and thick, the end blunt and roughened 
by minute points; the division between the basal wings 
runs as a suture an unusual distance up the broad 
column. The dorsum of the ninth segment is conspicuous 
as a triangular well-chitinised piece. 
Resinea (fig. 65), unlike alpina, has the wings of the 
tenth sternite forming a very low and flat arch, and the 
body, rising from them already narrow and as a thin pillar, 
tapers almost to a point. No other species has the pillar 
or body of the tenth sternite so slender and tapering. 
There are further eight species (of which five are British) 
