34 PROCEEDINGS OF THE ACADEMY OF [1885. 



NEW GENERA AND SPECIES OF FOSSIL COCKROACHES, FROM 

 THE OLDER AMERICAN ROCKS. 



BY SAMUEL H. SCUDDER. 



Since the publication of my essay on Palaeozoic cockroaches, 1 

 a considerable number of new types of Palseoblattarise have come 

 to hand, largely through the endeavors of Mr. R. D. Lacoe, to 

 whose favor I owe the opportunity of stud}-ing them, and partly 

 from my exploration of an interesting localit}' in South Park, 

 Colorado. Some of the former have since been published in a 

 revision of the species of Mylacris, 2 and the more interesting of 

 such as remain are described in this paper. 



The two new genera' of Mylacridae are closely allied to, but 

 differ considerabl} 7 from, the known genera. Of the Blattinariae, 

 the species of Oryctoblattina is the first secured from America, 

 and the Triassic genera and species are interesting, not only from 

 the deposit in which they occur, but also from their relation to 

 Carboniferous and Liassic types. 3 They will all be figured on 

 another occasion. 



PROMYLACRIS (rp6, /mXawpif), nov. gen. 



The mediastinal vein, though large and abundantly supplied 

 with veins, terminates not far beyond the middle of the wing ; 

 most of the branches fork more than once ; the scapular vein 

 runs in a nearly straight course, and terminates a short distance 

 beyond the mediastinal, playing a very insignificant part ; the 

 externomedian vein is far more important, crowding back the 

 scapular vein on the one side and the externomedian on the 

 other; the anal furrow is very deeply impressed and the anal 

 area strongly convex, its veins regular, frequent and strongly 

 curved. 

 Promylacris ovale, nov. sp. 



Represented by a single specimen and its reverse in a nodule 

 preserving well the anterior half of the body. The pronotum is 

 regularly arched, about one-fourth as high as broad, and twice as 



1 Mem. Bost. Soc. Nat. Hist., iii, 23, et seq. 



2 Ibid., iii, £99, et seq. 



8 Amer. Jour. Sc. (8), xxviii, 199, et seq. 



