1930] Permian Insects of Kansas 359 
of the wing is distorted by an irregularity in the surface 
of the rock. 
(7) Pusillus. The costal space is broadened basally, 
not straight, as shown in the figure of the type ; otherwise 
the shape of the wing is correctly represented. The ptero- 
stigma region is slightly darkened. The piece of limestone 
covering part of the posterior margin was removed, expos- 
ing the termination of Cul ; this vein is unbranched, not 
forked as supposed by Tillyard. There is a faint trace 
of a cross-vein between Cul and Cu2 at the base, but none 
is apparent distally. 
From these observations on the type specimens and a 
comparison with the Harvard fossils, I believe it is clear 
that most of the characteristics which Tillyard used to dis- 
tinguish the species do not hold. Furthermore, I am cer- 
tain that none of the type specimens have the very base 
of the wing preserved. Most of the Harvard fossils also 
seem to have the base of the wing broken away at a point 
near the maximum width of the costal space; but several 
of the specimens show a more basal part, where the costal 
space narrows again, and the posterior margin bends in- 
ward considerably, the wing becoming subpetiolate. This 
I believe to represent the true shape of the wing in the 
Fig. 2. Pterostigma of Doter minor Sell., with cross-vein; 
specimen No. 3101, Mus. Comp. Zool. 
