504 University Geological Survey of Kansas. 
mazona from Mazon Creek, Ill., by a fortunate fracture of the 
matrix, reveals the parts of the ovipositor before they have 
become united. An illustration of this specimen has been given 
in the writer’s paper on the “Structure of Paleozoic Cock- 
roaches,” referred to above. The ovipositor is here seen to 
consist of four approximately equal parts, or two pairs. A 
third smaller pair is probably present, although its preserva- 
tion is obscure. 
The naming of the wing veins is that coming into general 
use in entomological writings. Aside from the veins of the 
anal area five main veins of the wing are recognized. The 
costa of the front wing is doubtless marginal. A sharp fold 
is seen running across the humeral shoulder of the wing, and 
it is possible that the costa lies at the bottom of this fold. The 
subcosta is uniformly a moderately developed vein with from 
few to many superior branches, arising either in a cluster at 
or near the base (Mylacrinarixz) or as successive branches 
from the main vein (Blattinarix). The radial vein often 
comes close to the subcosta but with few exceptions remains 
free to the base. Its branches are superior, the earlier ones 
usually being compound. 
The hind wing of the cockroach, even as early as Coal 
Measure times, was essentially different from the front. A 
thinner and broader expanse of the wing is supported by a deep 
subcostal fold, a partial basal union of some of the main veins, 
and an imperfectly radiated arrangement of the veins toward 
the inner expanded side of the wing. The costa is submarginal 
and extends often one-half the length of the wing. It is 
usually simple, but occasionally gives off one or two superior 
branches. The subcostal fold is particularly well marked near 
the base of the wing, fading out toward the tip. The subcosta 
lies at the bottom of the subcostal fold and gives off branches 
beyond the termination of the costa. The radius is almost in- 
variably united for some distance with the subcosta and in 
such a way as to give it the appearance of a radial sector. 
That it is not the radial sector is, however, made evident by 
the fact that in rare instances it continues free to the base. 
According to Comstock and Needham® the reduction or ab- 
sence of the radial sector is a feature common not only to the 
hind wings of modern cockroaches, but also to the hind wings 
of all modern Orthoptera. The media of the more advanced 
306. Ameriean Naturalist, vol. XXXIII, p. 575, 1899. 
