TRICHOPTILUS PYGMAEUS 
189 
production of Plate XLVIII of the Pterophoridae of America; 
shows examples of each genus. The writer is indebted to Dr. 
Wm. Barnes for the use of the cut for this plate. 
In Fig. 10 are shown the wings of the only North American 
species without clefts. It will be noted that Rg reaches the apex 
of the primaries, and M. are weak, M 3 and CUi are long 
stalked, and 1st and 2nd A vestigial. This suggests that some 
veins may be lost by independent reduction and others by pro- 
gressive anastomosis, as is so often the case in the Lepidoptera. 
In the secondaries vestigial veins are even better illustrated, and 
one median, probably M 2 , is completely lost. 
The problems suggested by the comparison of wings of the 
cleft-winged genera are mostly simple. M^ and Mo are usually 
faintly evident as thickened lines at the base of the cleft in the 
primaries, and in Oidaematophoriis alone of our genera is one of 
them, M,, tubular. M. persists, showing a tendency to stalking 
with CUj. In no example is there evidence of extreme coalescence 
of these veins which would suggest incipient coincidence. On the 
contrary Adaina shows both GUj and CUg in a vestigial state, in- 
dicating the limitation of coalescence of the former with Mg and 
the reduction of both cubital branches by independent change. 
Unfortunately none of our genera in the Oidaematophorid series 
(Spuler's Pterophorinae) , including the genera with two anals in 
the secondaries, appear to be derived from this genus, so the 
possible results cannot be followed out. In the remaining genera 
