NO. 1441. AMERICA N PA LEOZOIC INSECTS— HANDLIRSCH. 763 



ARRHYTHMOBLATTA, new genus. 



Front wing somewhat curved, 2i times as long as broad. Costal 

 area very narrow, reaching- about three-tifths the length of the wing. 

 Radius not extending to the end of the anterior border, or scarcel}^ so, 

 with -i very oblique, simple, or furcate branches. Media very strongly 

 developed, with its 4 otfshoots, which branch off anteriorly and of 

 which the first forms several twigs, taking up the entire apical margin 

 and the terminal portions of the front and inner borders. Cubitus, 

 therefore, not reaching the end of the posterior margin, with 6 to 9 

 mainly simple branches directed backward. Anal area broad and 

 short, with about T veins. Interspaces between the principal veins 

 very wide in the middle of the wing. No distinct cross veins. 



Type of genus, Arrhythmoblatta detecta (Scudder). 



ARRHYTHMOBLATTA DETECTA (Scudder). 



Etoblattina detecta Scudder (part), Bull. U. S. Geol. Surv., No. 124, 1895, p. 75, 

 pi. IV, fig. 12 (not fig. 13). 



Locality. — Cassville, West Virginia. Dunkard formation; Lower 

 Permian. 



6V?%My.— Cat. No. 380S4:, U.S.N.M. 



ARRHYTHMOBLATTA SCUDDERIANA, new species. 



Etoblattina detecta .Scuddek (part). Bull. \J. 8. Geol. 8urv., No. 124, 1895, p. 75, 

 pi. IV, fig. 13 (not fig. 12). 



Locality. — Cassville, West Virginia. Dunkard formation; Lower 

 Permian. 



LLjlotyjje.^Q,9X. No. 3S894. U.S.N.M. 



AMETROBLATTA, new genus. 



Front wing of more compressed form, subreniform. Costal area 

 extending two-thirds the length of the wing. The radius with its 

 branches, in addition to the anterior margin, takes up a large part of 

 the apical border; the 4 divisions branch off forward and the first is 

 furcate, the second separates into 6 twigs, the third into 3 twigs. In 

 the figure, the media is represented as a simple unbranched vein. The 

 cubitus divides close to the base into one long superior branch, several 

 twigs of which are given off' to the apical border, and into the inferior 

 branch that continues obliquely to the extremity of the inner margin 

 and gives off' posteriorly about 6 branches. The large, broad anal area 

 is limited by a strongly curved fold and contains about 7 veins. Cross 

 veins are not to be seen distinctly. 



Type of genus, Ametrohlatta s^r^^6>5» (Scudder). 



