ARTHROPOD A— IN SECTA. 



433 



of the front wing more reduced and supplanted by a great number 

 of branches extending forward from the radius, which together 

 with the media is crowded back by the strongly developed cubitus. 

 Example: Gerapompus blattinoides Scudder (Fig. 1735), from 

 oMazon Creek, 111. 



The family Adiphlebidce with 2 species is characterized by an 

 enlarged shield-shaped pronotum, and by having the branches of 

 Sc, R, M, and Cii, run off almost ray-like from the base of the 

 wing, separated by numerous intercalary veins, and many cross- 

 veins. Example: Adiphlebia lacoana Scudder (Fig. 1736) from 

 the Mazon Creek beds of Illinois. 



Finally in the family Anthracothremmidce , with only one species. 

 Anthracothremma robusta Scudder (Fig. 1733,1), from Mazon 

 Creek, the wings differ from all other 

 Carbonic insects hitherto known. The 

 front wings are slender, four times as 

 long as wide, with strongly arcuate an- 

 terior border, a very narrow costal area, 

 extending about two thirds the length 

 of the wing, and a short anal area, 

 marked off by a bow-shaped furrow ; R 

 simple, reaching nearly to the tip of the 

 wing; Rs emerging near the base of the 

 wing, with four or five simple branches 

 which extend in a curve to the apical 

 border; branches of M and Cu nearly 

 parallel ; hind wings similar, but with 

 subcosta extending farther towards the 

 tip. The body is robust; prothorax enlarged, disk-shaped; front 

 legs somewhat elongated as in Eiiccenus. 



Fig. 1736. Adiphlebia la- 

 coana Scudder, X |> Mazon 

 Creek, 111. Carb. (After 

 Scudder. ) 



Order BLATTOIDEA Handlirsch. (Cockroaches.) 



This order includes the majority of Palaeozoic insects, a total of 

 more than 620 species being known, of which approximately 289 

 are North American. These are distributed as follows : Kanawha 

 horizon 4, Kittanning 56, Freeport 37, Conemaugh and higher coal 

 measures 92, Lower Permic 100. Scudder separates the Palaeo- 

 zoic cockroaches from the Mesozoic and later species as Pal^o- 

 28 



