188 
A. W. LINDSEY 
specimens showed variations in neuration. One had Cug well 
marked, tubular, though weak, but this specimen lacked R^. 
Other wings were then examined which showed no trace either 
of Ri or Cu^. The figure (Text fig. 1) is therefore a composite 
showing all veins known to appear in this species. It will be 
seen that it differs so little from the wings of other species now 
FIG. 1. TRICHOPTILUS PYGMAEUS WLSM NEURATION. 
included in the genus (Plate XX, fig. 1) that the retention of the 
present association is justified. The condition of the neuration 
indicates, however, that pygmaeus is in a state of evolution which 
may ultimately produce a much simpler wing than is now found 
in the species. 
In consideration of the diversity of genitalic structure ex- 
hibited by the North American species, no analysis of relation- 
ships can be drawn from this source. The genitalia of pygmaeus 
are figured (Text fig. 2) for specific identifications. The figure 
is taken from a camera drawing of a prepared specimen which 
was slightly distorted on the slide. No appreciable asymmetry is 
actually present. 
It occurred to the writer while working on the wings of this 
species that the neuration of the Pterophoridae as treated by 
Meyrick in the Genera Insectorum and by Barnes and Lindsey 
in the Pterophoridae of America is probably incorrectly inter- 
preted. Our North American genera furnish enough types of 
neuration to illustrate the problem nicely, and Plate XX, a re- 
