CARBONIFEROUS COCKROACHES. 413 



particularly noticed that its form as well as the character of its main venation bears a 

 striking resemblance to the wings of Dictyoneura and its allies. The only well marked 

 difference is, perhaps, in the costal area where its alliance to the fore wing of the Pal- 

 aeoblattariae appears. Owing to the obliteration of the attachments of the main veins, 

 very great uncertainty must remain as to the normal veins to Avhich any of the longitud- 

 inal nervures belong; the mediastinal vein, however, is clearly marked; it runs in very 

 close proximity to the margin, not farther from it than the other nervures are separated 

 from each other; it terminates just about as far from the tip of the wing as in the front 

 wing and emits a large number of necessarily short but very oblique and generally forked 

 branches. Following it are at least five principal nervures, all of which seem to belong to 

 preanal areas, but any two or more of which may belong to the same principal vein, so 

 far as anything can be stated from this specimen. The first, counting from the medias- 

 tinal vein, is forked at a point exactly similar to the basal forking of the scapular vein of 

 the fore wing and in a similar way, and hence may be presumed to be that vein ; this 

 basal forking of the presumed scapular vein can only be seen in the left Aving, where the 

 upper branch is simple; the lower branch, however, is seen distinctly in both wings to 

 fork exactly opposite the second forking of the lower scapidar branch of the upper wing ; 

 the forks, however, act differently in the two hind wings: on the left side they both 

 fork, the upper halfway, the lower three-quarters way to the margin ; on the right side, 

 the lower is simple, while the upper forks before the middle and its lower branch forks 

 again halfway on its course; the number of nervules reaching the margin is thus the 

 same and they cover the same narrow space, the lowermost striking the tip. Judging 

 from the analogy of the upper wing, the next two nervures, which are exactly alike in 

 the two hind wings, belong to the externomedian vein, in which case they repeat almost 

 exactly the characteristics of the same vein in the upper wing of the left (but not of the 

 right) side, forking first (to judge from the gradual approximation of the two nervures 

 baseward) at or a little before the end of the middle third of the wing, the lower fork 

 again branching at some distance beyond the middle of the wing, and the upper halfway 

 between this and the tip. Below these are, first a forked nervttre and then a simple one, 

 both of which probably belong to the internomedian vein, but do not resemble the same 

 part in the upper wing; the forked vein forks as far from the margin as (but of course 

 further from the tip than) the upper externomedian branch : in the left wing it is simply 

 branched; in the right it sends a similar oflTshoot from both sides of the stem, *. e., it 

 divides into three at the same point; all these nervures are very long and straight with 

 a slight downward sweep as they approach the margin, especially in the upper part of 

 the wing; they are about as distant fi'om each other as in the upper wing but, particularly, 

 the lower ones are less oblique ; on the left wing there is also another fragment of a simple 

 vein, as far below the lowest mentioned as the latter is from its predecessor and trend- 

 ing slightly toward it baseward; it probably also belongs to the internomedian vein. 



Besides the wings, a part of the i;)ronotal shield is present, and the limits of the abdo- 

 men are partly marked by a depression. The former is nearly semicircular, somewhat 

 broader than long, very regularly rounded in front, the sides very slightly divei-gent be- 

 hind the middle; the posterior edge appears to be scarcely convex; a little to the outside 

 of the middle of either lateral half is a slight rounded furrow or depression, less curved 



