H. Bolton—A New Species of Fossil Cockroach. 149 
mediastinal vein, breaking up into fine tertiary veins, the first two of 
which again fork before reaching the margin. The median branch of 
the scapular divides into two equal tertiaries, the anterior forking 
twice before reaching the margin, and the hinder forking but once. 
The scapular area occupies a little less than the outer half of the 
anterior margin of the wing, and almost exactly half of the external 
margin. Notwithstanding a general correspondence of the scapular 
vein with that of #. venusta, it occupies more of the anterior margin, 
owing to the forward curve of the anterior secondary vein, a curve 
which is continued in the tertiary branches, causing them to reach the 
margin a little beyond the middle of the latter’s length. 
Anal veins 
Moediasttnal----}---- \\ 
Scapulap-}---; Anal furrow 
Externomedian~, \| Internomedian 
~~ 
x 3 
% 
& y 
2 
& is 
: 
& y 
; 3 
5 
3 8 
Q m 
~ 
.~ 
3 
3 
Outline figure of one of the tegmina of Ztoblattina mazona, from the Carboniferous 
beds of Illinois, with the nomenclature of the veins as used by Heer and followed 
by Scudder (see Bulletin U.S. Geological Survey, No. 124, 1895, ‘‘ Revision of 
the American Fossil Cockroaches, etc.,’’ p. 37, fig. 3). 
The externomedian vein follows a sub-parallel course to the hinder 
secondary of the scapular, and remains undivided until it reaches the 
secondary forking of the latter. In this respect, the specimen again 
differs from ZL. venusta, where the forking occurs at a lower level. 
An examination of Scudder’s drawing shows that the primary forking 
of the externomedian, and the secondary forking of the scapular, lie 
in an oblique line directed forwards and outwards, whilst in the 
present case the same points of division lie upon a straight line 
bisecting the wing. The externomedian in the present specimen 
shows no internomedian branch in its lower third such as is indicated 
by Scudder. Beyond the first fork the hinder branch divides twice, 
so that the externomedian divides up into four branches, all of which 
reach the margin without further subdivision. The externomedian 
area is very small, and subtends not more than one-third of the tip of 
the wing. The internomedian vein follows a course parallel to the main 
axis of the externomedian, and after curving backwards a little in the 
first quarter of its length, passes straight outward to the hinder edge 
of the wing tip, giving off to the inner margin nine simple straight 
and unforked branches. The marginal area occupied by this vein and 
