788 



PROCEEDINGS OF THE NATIONAL MUSEUM. ' vol. xxix. 



NEOMYLACRIS PAUCINERVIS, new species. 



Locality. — Lorbeny (jap in 8har}) Mountain, near Tremont, Penn- 

 sylvania. Anthracite series; staged 



Fig. 9G. — Neomylackis pai'ctnervhs. 



Length of front wino-. 10 mm, Ver\' similar to the previous 

 species. Radius witli 3 furcate and 2 simph^ brandies. Media tirst 

 furcates in the last third of the length of the wing. 



Holotype.—Q^t. No. 38789, LT.S.N.M. 



Family KrERIDOMYLACRlD^F], new family. 



I erect this family on an aberrant blattoid form, whose heart-shaped 

 wing, in respect to the shape of the costal area, conforms to that of 

 the mylacrids; \\\ its enormousl}' lengthened anal area, which attains 

 a])out four-fifths the length of the wing, however, it widely differs 

 fi'om all other IjJattid forms. The radius is developed in the normal 

 way; the media and the cubitus, on tlie contrary, are much reduced. 

 The veins of the anal area end in the inner border. 



Indeed, no other blattid wing shows so striking a resemblance to the 

 pinna? of a fossil fern, and I was for a long time in dou})t whether the 

 present specimen should really be regarded as the remains of an insect 

 or as a plant. We here seem to have a form showing an extreme 

 adaptation. 



PTERIDOMYLACRIS, new genus. 



Front wing cordate, \^ times as long as l)road. Costal area trian- 

 gular, attaining nearly two-thirds the length of the wing, with ray-like 

 veins issuing from one point. Radius advancing to the apical border, 

 with about 7 regular branches, probabl}' simple throughout, extending 

 to the anterior margin. Media arcuate, with one shoil terminal fork. 

 Cubitus with one compound and one simple branch, which strike the 

 end of the inner margin. Anal area strongly developed, reaching 

 four-tif ths the length of the wing, and marked off by a curved suture, 

 with 10 veins ending in the posterior margin, several of which have a 

 common origin. No structure to be seen. 



