No. 386. ] THE WINGS OF INSECTS. 125 
these three insects differ as much from each other as do the 
more generalized members of widely separated orders of living 
insects. 
Evidently, comparatively high specializations in widely 
o- 
oor 
--* 
-- 
nonn” 
s.. 
..- 
- 
a* 
- 
PONOSNA 
a 
Paawrsiesaee x 
Fic. 73. — Platephemera antigua. 
different directions had been attained already at that early time. 
But the point to which we wish to call especial attention is 
that, of the three better-preserved Devonian insects, one (Xeno- 
neura) had but few wing-veins. And when we consider the 
