.1 MERICA N PALEOZOIC INSECTS— HANDLIRSCH. 791 



Family POROBLATTINID.E, new family. 



This family is founded oiva numl)er of spiall forms from the Upper- 

 most Carboniferous and Lower Permian. These forms constitute a link 

 between the arehimylacrids and the prevailing- Mesozoic mesoblatti- 

 nids, and are characterized by a strongly reduced costal area, which 

 extends only from one-third to one-half the length of the wing and is 

 of rather narrow lancet-like shape. In contrast with the mesoblatti- 

 nids, however, the few branches of the subcosta are still distinctly 

 developed, and arise from the subcosta serially as in the arehimyla- 

 crids. The radius ver}^ gradually takes the place of the subcosta and 

 forms numerous simple or feebly divided branches directed forward. 

 The media is free and sends out a small num])er of olishoots forward 

 to the apical border; the cubitus gives otf a variably largo number of 

 branches backward; rarely, also, one forward. The anal area is rela- 

 tively large, limited by a strongly curved suture, and contains numer- 

 ous veins, of which the lirst ones only end in the suture; all others, 

 on the contrary, end in the inner border. No distinct cross veins. 



POROBLATTINA Seudder. 



Porohlattina arcuata Seudder is to be regarded as the type of tlvis 

 genus. 



Front wing subelliptical. If to 2 times as long as broad. Radius 

 very strongly arcuate, curving down to the middle of the wing and 

 recurving to the apical border. Media first divides below the middle 

 of the wing. Cubitus with few branches and not occupying the entire 

 free posterior border, strongly vaulted. Anal area half as long as the 

 wing and less than twice as long as high, with numerous oblique veins 

 directed toward the apex of the area, the larger number of which end 

 in the inner border. No structure to be seen (many oblique cross 

 folds ])etween the veins). 



POROBLATTINA BRACHYPTERA, new species. 



L^calHy. — Wills Creek, near Steubenville, Ohio. Conemaugh for- 

 mation; shales above the Ames limestone. 



FlO. 99. — POROBLATTINA BRACHYPTERA. 



Front wing, 9 mm. long; twice as long as broad. Radius with about 

 11 l>ranches, the first 8 of which are simple. 

 /A>Wv;>.^— Cat. No. ?,SB?>7, U.S.N.M. 



