AX APPAREXTLY XEW PROTOBLATTID FA^IILY FRO^I 

 THE LOWER CRETACEOUS 



Bv EVELYN GROESBEECK MITCHELL 



The following description is based on a single nearly perfect wing 

 found in association with numerous species of plants in the Kootanie 

 beds (Lower Cretaceous) of the Great Falls coal field, Montana. It 

 is noteworthy that all other Protoblattids appear to be from the Car- 

 boniferous, the American forms coming from the Alleghany stage. 

 It was detected by Dr. F. H. Knowlton while studying the plants, 

 and by him placed in my hands for investigation. It has been care- 

 fully compared with such specimens of the Protoblattoidea as are 

 contained in the collection of the United States X^ational Museum, 

 as well as with the available literature on the subject, especially the 

 recent work of Handlirsch, with the result that it appears to repre- 

 sent not only a new genus and species, but a new family. It may 

 be named and characterized as follows : 



Superfamily PROTOBLATTOIDEA Handlirsch 

 Family Lvgobid.ii;, new famil}- 



This family seems intermediate between Oryctoblattinidse Hand- 

 lirsch and Eucsenidse Handlirsch of the Carboniferous. The main 

 venation would seem to place Lygobius among the Eucjenid?e. but 

 the latter entirely lacks intercalary and cross-venation, which are 

 prominent characteristics of the former. This last venation much 

 resembles that of some of the Oryctoblattinidae, but the strongly com- 

 pound radial sector of the latter family is in distinct contrast to the 

 almost simple radius of the new famil}'. 



The Lygobidse is also characterized by the extension of the cubital 

 area, which comprises nearly half the width of the wing; the com- 

 paratively few-branched medius ; almost complete intercalary vena- 

 tion and numerous cross-veins, especially regular in the distal half 

 of the wing, and a costal area apparently broad, especially at tlie 

 base. 



LYGOBIUS, new genus 



Cubitus strongly compound, with branches directed obliquely 

 backward and presenting a typical forking, with strong intercalary 



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