412 SAMUEL H. SCUDDER ON 



little before the end of the middle thii-d, a very little sooner than on the opposite "wing, 

 and each of these branches is again forked, the upper the nearer to the outer margin, 

 and at the same distance from it as the apical fork of the opposite wing. The externo- 

 median vein also differs in a single point very markedly in the two wings; it occnpies 

 more space by its earlier division in the left wing, but in neither does it dilFer miich from 

 the preceding in the extent and form of the area which it covers: in the left wing it di- 

 vides at the end of the basal third of the wing, just beyond the initial forking of the 

 scapular vein; in the right it does not fork until it has reached the middle of the wing; 

 notwithstanding this difference the rest of the area has the same aspect ; the lower branch 

 forks a little beyond the middle of the wing, and the upper at about the end of the mid- 

 dle third, the nervules being entirely simple, and this brings the secondary forking of 

 this vein close to its primary forking in the right wing, although far from it in the left. In 

 addition to these peculiarities, this vein possesses another in the presence of a short cross 

 vein running oljliqnely like an ordinary branch from before the end of the basal fourth 

 of the wing to the internomedian vein, which it strikes at or barely beyond the origin of 

 the second branch of the same. The internomedian vein with its outermost branch strikes 

 the inner margin near the middle of the outer half of the wing, thus occupying on the 

 border considerably more space than either of the preceding two veins; it is considerably 

 arcuate and emits from its lower border three principal veins, the iirst two simple, the 

 outermost forked, and differing in the two wings ; the first vein is sent forth opposite the 

 base of the cross shoot of the preceding vein, the next a little beyond it or a little before 

 the end of the middle third of the wing, while the third originates at a greater distance 

 off", in the middle of the wing opposite the fork of the lower branch of externomedian 

 vein: on the left wing, the inner fork is simple, the outer forked again in the middle 

 of its course, or it might be said that the main stem had four principal and all simple 

 branches; in the right wing, both forks subdivide, the inner halfway, the outer at much 

 less than halfway, to the margin. The anal furrow is very arcuate near the base and at 

 this part deeply impressed, beyond nearly straight and hardly impressed, running vei-y ob- 

 liquely and terminating on the inner margin not very far before the middle of the wing; 

 the anal veins count about eight at the margin; they are much simpler on the right than 

 on the left wing, having in the latter three wliich fork and one of these an interjiolated 

 one which connects with those on either side by an oblique cross vein; while most of 

 those on the right wing are simple, one forking close to the base, another near the 

 middle; they are all considerably arcuate. The differences therefore between the two 

 wings are considerable in the minuter details, though imjiortant only in the first branch- 

 ing of the externomedian vein, which strangely does not affect the subsequent offshoots 

 of the same. 



The hind wing of each side is also present to a considerable extent. More perhaps 

 can be said of its form than in almost any other paleozoic cockroach hitherto described. 

 The wing, except in lacking altogether any convexity in its straight costal margin until 

 the narrowing of the wing begins toward the apex, closely resembles in form the fore 

 wing; it is of just about the same length and breadth also, a point which appears to dis- 

 tinguish the ancient from the modera tyi)cs; so far as we know, the hind Avings of the 

 former gi'adually taper apically to a well and very regularly rounded apex. It should be 



