,1 M ERICA N PA LEOZOIC IXSEi 'TS— HA NDL TRSCTT. 793 



The radius appear.-s to extend to the apical margin, but is oentl}' 

 curved, and notwithstandiiiu' tliis conthuies down toward the middle 

 of the wing. The media divides about in tlu> middle of the wing, and 

 th(^ cubitus is very much retluced. No cross veins. 



? SYSTOLOBLATTA OHIOENSIS (Scudder). 



Porolihilliiia Dhiiinisls Sciddkk, ISull. [' . S. ( Icol. Siifw, No. rJ4, iSilf,, p. i;;s, 

 pi. \i. 11,^. -. 



A/^/r^//////. — Kichinond, Ohio. Conelnaugh t'oi'mation: shales abo\<' 

 the Ames limestone. 



Family MESOBLATTINID.E, new family. 



This family, which is very feebly represented in the Paleozoii-. but 

 is very abundantly developed in the Mesozoic, is characterized by a 

 most remarksible reduction of the costal area, the place of which the 

 radius with its branches now tills. The media is free and is divided 

 in vai'ious ways, as is also the cubitus. Most of the veins of the anal 

 area reach to the inner margin. This group can be ({uite readily 

 derived from the poroblattinids. 



ACM^^OBLATTA, new genus. 



Front wing pointed, nearly o times as long as broad. Radius reach- 

 ing nearly to the tip, with very many branches. Media with about <> 

 simple offshoots branching out forwai'd. C'ubitus with about i' simple 

 (;') branches occupying the middle third of the inner margin. Anal 

 area relatively long and narrow, its veins, at least in part, parallel 

 with the posterior bordei'. No cross veins visible. No intercalary 

 veins. 



ACM.^OBLATTA LANCEOLATA, new species. 



Jjx-al'itii. — Wills Creek, near Steubenville, Ohio. C'onemaugli for- 

 nr.ition; shales above the Ames limestone. 



Fk;. 102. — AlM.l';oBLATTA I,.\NCEOLATA. 



Front wing, lU mm. long. Radius with about 14 mainly sim])le 

 veins. The first branch of the media originates near the base. 

 Ilolotypt'.—Cat. No. 3867S, U.S.N.M. 



