with Descriptions of New Forms. 



223 



border near the base is quite concave, and the wing otherwise 

 shows evidence of a specialized condition. The subcosta, 

 radius, and media are united for some distance from the base. 

 The first to separate is the media, which occupies a compara- 

 tively narrow area, branching first about the middle of the 

 wing, its divisions running to the apex. The radius then 

 separates from the subcosta 5 or 6 m,n from the base, and reaches 

 almost to the apex. The subcosta has only a few thin supe- 

 rior branches. The cubitus has the typical, very oblique, 

 mostly simple veins. The anal area is long and has a few 

 curved, forked, and rather loosely placed veins. Length, about 

 1T mm . w jdth, 9 or 10 min . Figures 34 and 35. 



33 34 



36 



■35 



Figures 33-36. — Hind wings. Figure 33, Etoblattina sp. ; Figures 34 and 

 35, undetermined ; Figure 36, Promylacris rigida, from the type specimen ; 

 all twice natural size. Originals of Figures 33 and 35 in University of Kan- 

 sas Museum ; of Figure 36 in the National Museum. 



Formation and Locality. — Lawrence Shales, Upper Coal 

 Measures, Lawrence, Kansas. Types in the University of 

 Kansas collection. 



General Considerations. 



The cockroaches have proved themselves a remarkably per- 

 sistent type. They are known to range in time from the 

 Middle Carboniferous to the present, and doubtless took their 

 origin somewhat earlier. The Carboniferous representatives, 

 as described above, were in many respects much like their 

 modern descendants. The body had, as Scudder has well said, 

 essentially the same shape. The legs indicate the same habit 



