CLASSIFICATION OF PALEOZOIC INSECTS. 335 



tie shouldered near the base. Marginal vein bordered on the proximal half of the wing by 

 a very narrow and tapering membrane, so that it does not form the actual margin until 

 beyond the middle of the wings. Mediastinal vein parallel to it, impinging ou the scapular 

 a little before the end of the middle third of the wing, and running nearer the marginal than 

 the scapular vein. Scapular vein gently arcuate, running in the proximal half of the wing 

 in a straight course parallel to the marginal vein, then bending slightly upward to meet 

 the top of the mediastinal, and in the apical third of the wing curving gradually downward, 

 a little less rapidly than the marginal so as to unite with that not far before the extreme 

 tip (which is broken oft); very far toward the base of the wing (near the middle of the 

 basal fourth) the inferior offshoot originates, and runs completely parallel to the marginal 

 vein until it forks, at or just bej'ond the tip of the mediastinal vein ; each of its forks 

 again subdivides in the left wing, at no great distance from the border, the upper one 

 more distant from it than the lower ; but in the right wing the upper fork is simple, and 

 the lower as in the opposite wing. The externomedian vein forks near the base, next 

 the origin of the scapular branch, and its branches pass in a broad curve to the tip of the 

 inner margin, the lower one simple, the upper forked apically. the fork being deeper on the 

 right wing than on the left, where, in this feature, it stands midway between the two forks 

 of the scapular branch. The internomedian vein is a little obscure except in the apical por- 

 tion, where the veins originate a very little earlier on the left wing thin on the right ; it 

 parts from the neighborhood of the other veins next the forking of the preceding vein, and 

 passes first in a straight line to just about the centre of the wing, when it sends a straight 

 oblique branch to the middle of the apical half of the lower margin ; it then takes a course 

 sub-parallel to the costal margin, very soon emits another similar branch, and finally forks 

 opposite the tip of the mediastinal vein ; Avhether it also emits some branches nearer the 

 base is uncertain, but it is probable that either there is a single one thrown oif close to the 

 base, parallel to those beyond ; or that all the nervules within the first distinct branch 

 belong to the anal vein ; these last nervules are obscure, but appear to repeat the course 

 and separation of the internomedian veins. 



Hind wings shaped as the fore wings, but more ample, extending at rest, like the fore- 

 wings, beyond the tip of the abdomen, which reaches about the middle of the distal half. 

 Little of the neuration can be made out, but the apical half of the scapular vein appears to 

 be the same as in the front wing. The internomedian vein is strongly curved before it 

 forks in a sense opposed to the general course of the curving veins; it first branches a lit- 

 tle before the middle of the wing, and in sending out its three or more branches (a little 

 nearer the base than in the front wing) it turns parallel to the costal margin, and its 

 branches part at a much wider angle and pursue a much more transversely oblique course 

 than in the front wing. The anal area is probably not any fuller than in the front wing, 

 for the hind wing of the right side shows hy its apical margin, beneath the front wing of the 

 left side (a margin not shown in the figure), that if there were any fulness to its anal area 

 it should appear beyond the costal margin of the left front wing. 



Length of body, from extremity of head (exclusive of mouth parts) to tip of body 

 (exclusive of anal cerci), 34.5 mm., of mouth-parts, 2.5 mm., of head. 3.25 mm., of pro- 

 thorax, 5 mm., of mesothorax, 5.75 mm., of anal cerci, 2.5 mm., of front wing, 31 mm., 

 breadth of head, 2.25 mm., of prothorax, 3 mm., of mesothorax, 9 nun., of front wing, 

 10 mm. 



