ARTHROPODA—INSECTA. 



431 



forms are: Propteticus infernus Scudder (Fig. 1732) from the 

 AUeghanian of Vermilion County, 111., Dieconeura arcuta Scudder 

 (Fig. 1733-4) and Genentomum validum Scudder (Fig. 1733, 

 2, 3), both from the AUeghanian of Mazon Creek, 111., the last 

 representing a family, in which the superior branch of the M of 

 the front wing coalesces with the Rs and later again separates. 

 In the Permic occur : Lepium elongatum Sellards ; Stoichiis Sellards, 



Fig. 1733. Protorthopterous insects from coal measures of Mazon Creek, 111. I, 

 Anthracothremma robusta, X f > 2, Genentomum validum, front wing, X f > 3> ^lind 

 wing of same, X I > 4> Dieconeura arcuta, X !• ^^W after Scudder.) 



several species; Lemmatophora Sellards, 5 species; Artinska Sel- 

 lards, 6 species, etc. 



Order PROTOBLATTOIDEA Handlirsch. 



Head distinct, rounded; prothorax either not expanded, or only 

 moderately so ; wings intermediate in character between the palaeo- 

 dictyopteran and the blattseform type, laid back over the abdomen 

 when at rest; front wings with anal area fairly well defined, and 

 filled up with arcuate or oblique veins descending to the posterior 

 margin ; hing wing with enlarged anal area, defined by fold. 



Of the 44 or more known species, 2"/ are American, 19 occurring 



