54 S. II. SCTJDDER ON PALAEOZOIC COCKROACHES. 



the stone, is parallel to that of the scapular veins of the front wing. In distinction from 

 the veins of the front wing, these are slightly elevated, and the basal half of the fragment 

 has a glistening surface, while that of the apical half is dead and shows exceedingly taint 

 traces of transverse wrinkling like the cross neuration of the front wing. If, as the direc- 

 tion of the veins leads us to suppose, the wing is that of the opposite side of the body, and 

 has its natural position as closed, the hind wing of this insect must have been very broad, 

 broader indeed than the remains of any other palaeozoic cockroaches would lead us to 

 presume in them. 



Notwithstanding the fragmentary nature of the fossil, it is plainly distinct from any 

 other known form. The structure of the mediastinal vein, although approximating to a 

 certain degree that of the Blattinariae, plainly shows it to belong to the Mylacridae, and is 

 indeed not very different from the same vein in Lithom. angustum, while the very arcuate 

 form of the internomedian vein, combined with the great breadth of this area, separate it 

 at once from all the species of Mylacridae mentioned here. Its generic affinities with 

 Necymylacris are doubtful, and the material is insufficient for accurate determination of all 

 the points which should be settled before reference to a distinct genus can be made, but 

 it agrees with that genus to a certain extent in several points in which it differs from other 

 Mylacridae, and especially in the mediastinal vein (although it is here very much simpler 

 than in Necym. heros — as indeed is the whole neuration) and in the anal area, whose extent 

 and the distribution of whose branches, and particularly the character of the compound 

 branch next the anal furrow, is very similar. 



The single specimen known (numbered 2009) was found by Mr. R. D. Lacoe in the 

 lowest productive coal measures near Pittston, Penn., and by him sent me for examination. 



Necymylacris heros nov. sp. PI. 5, tig. 9. 



Fore wing. The wing is loug and slender, very long obovate, nearly ecpud ; the costal 

 margin is very gently convex, nearly straight along the middle, the inner margin even less 

 convex, and the gently tapering apex rounded; the veins originate from near the middle 

 of the base of the wing, and most of them curve upward a little for a short distance. The 

 mediastinal vein is at first directed toward the middle of the basal half of the costal 

 margin, but close to the base bends abruptly, and runs in nearly a direct line to the middle 

 of the outer half of the costal margin, separated therefore by a straight line from the 

 scapular area; next the humeral lobe, which is smooth, are two or three weak radiating 

 veins which spring from the base of the principal vein; but most of the slowly narrowing 

 mediastinal area is filled with scarcely radiating branches which spring unequivocally from 

 the main vein beyond the base; there are three such principal branches, all originating in 

 the basal third of the wing and compound, besides a simple apical branch near the tip; 

 each of these compound branches, which are as nearly longitudinal as their position 

 allows, emits, generally at some distance from its base, two or three outer simple or 

 forked branches, so that the costal margin is filled with crowded veins. The scapular vein, 

 gently arcuate until it divides, near the middle of the basal half of the wing, is thereafter 

 straight, running down near the middle line of the wing and parallel to the costal margin; 

 a little beyond the middle of the wing, however, it is deflected very slightly upward, 

 the change being scarcely perceptible, and terminates on the apical margin just before the 



