790 



FROCEEDINGS OF THE NATIONAL MUSEUM. 



Vt)L. XXIX. 



IDIOMYLACRIS, wew genus. 

 IDIOMYLACRIS GRACILIS, new species. 



Locality. — Lorberiy (nip in Sharp Mountain, near Tremont, Penn- 

 sylvania. Antliracite series; stage ? 



Pig. 9S. — Tdtomylacris gracilis. 



Length of the front wing, about 15 mm. 

 IIolofi/j)e.— Cat. No. 38793, U.S.N. M. 



Family NEORTHROBLATTINIDiE, ne^ family. 



I establish this family on a somewhat aberrant blattoid form, which 

 unfortunately I can judge only from Scudder's figure and discription. 

 The venation somewhat recalls that of Miomylacrh from the Upper 

 Carboniferous and permits itself very easily to be derived from the 

 archimylacrid type. The outline of the wing appears to have been 

 subreniform, with somewhat broadened base, and rather more than 

 twice as long as wide. The short, broad costal area reaches over a 

 little beyond the middle of the wing, and the form belongs to the band- 

 shaped type (Archimylacrida?, etc.); the veins issue successively from 

 the subcosta. The radius extends to the upper end of the apical bor- 

 der and sends out only a small rumiber of branches toward the front 

 margin. About in the middle of the wing, the media divides into 2 

 simple or furcate branches. The cubitus continues to the end of the 

 posterior border and sends out several branches to it. The anal area 

 is large, marked oil by a bow-shaped fold, and contains a small num- 

 ber of veins, which branch off in a peculiar manner, similar to that in 

 Idiomylacris, in part again uniting; they all end in the inner margin. 

 On the impression, the surface of the wing appears very opaque; the 

 veins, on the contrary', are preserved as thin broad stripes. 



NEORTHROBLATTINA Scudder. 

 NEORTHROBLATTINA ALBOLINEATA Scudder. 



NeorthrohlaUvna albohneata Scudder, Proc. Acad. Nat, Sci. PJhila., 1885, p. 109; 

 Mem. Boston Soc, IV, 1890, p. 467, pi. xui, fig. 2 (? 18). 



Locality. — Fairplay, Colorado. Lower Permian. 



