DISTRIBUTION 207 
number and variety, still restricted, however, to the more 
generalized orders. The dominance of cockroaches in the 
Carboniferous is especially noteworthy, no less than 200 Palzeo- 
zoic species being known from Eu- 
rope and North America. These 
Fic. 297. 
ancient roaches (Fig. 297) differed 
from their modern descendants in 
the similarity of the two pairs of 
wings, which were alike in form, 
size, transparency and general neu- 
ration, with six principal nervures 
in each wing; while in recent cock- 
roaches the front wings have be- 
come tegmina, with certain of the 
veins always. blended together, 
though the hind wings have retained 
their primitive characteristics with a 
few modifications, such as the ex- 
pansion of the anal area.  Car- 
boniferous cockroaches furthermore 
exit OVIPOSILOTS, Straight,-slender, — Bteblaitina: mazond, 2) Cer. 
boniferous cockroach from 
and half as long again as the abdo-  tinois. Twice natural size. 
—After ScuppEer in Miall and 
men—organs which do not exist in 5, 
Jenny. 
Recent Species. 
Lithomantis (Fig. 298), a remarkable form from Scotland. 
possessed in addition to its four large neuropteroid wings, 
a pair of prothoracic wing-like appendages which, provided 
they may be regarded as homologous with wings, represent 
a third pair, either atrophied or undeveloped—a_ condition 
which is never found today, unless the patagia of Lepidoptera 
represent wings, which is unlikely. 
From the rich deposits of Commentry, Brongniart has des- 
cribed several forms of striking interest. Dictyoneura is a Car- 
boniferous genus with neuropteroid wings and an orthopteroid 
body, having, in common with several contemporary genera, 
strong isopteran affinities. Corydaloides scudderi, a phasmid, 
