80 FOSSIL INSECTS OF THE BRITISH COAL MEASURES. 



the first branch of the median, and remains parallel with it over almost the whole 

 of its length. Inwardly it is separated somewhat widely from a slighter vein 

 which, I believe, joined it near the base, and formed the first inward branch. The 

 main stem sends off at the middle of the wing- a strongly curved branch which 

 bends first inwards and then outwards towards the apex, breaking up into five 

 twigs before reaching* 1 the inner margin. The second of these twisrs forks. A 

 second undivided branch comes off a little further out, and a third very small one 

 almost on the margin. The next two veins were probably united a little way out 

 from the base, and their direction is such that the single stem from which thev 

 arose may have arisen, as suggested above, as the first inward branch of the 

 cubitus. The outer of the two veins is undivided, and reaches the inner margin 

 beyond the middle of the wing. The innermost vein runs fairly parallel with the 

 first along its whole length, giving off, as it does so, four inwardly directed twigs, 

 of which the first and fourth fork. The whole vein ends on the margin in six- 

 twigs. Four anal veins are shown, one only forking. 



The interstitial neuration of the radial and median areas consists of straight 

 or slightly curved nervures, placed at nearly equal distances. The very wide 

 cubital and cubito-anal areas are filled by a loose meshwork, and a few irregular 

 wavy nervures. The anal area is crossed by simple straight nervures. 



Affinities. — Scudder was originally of opinion that this wing was related to 

 Meganeura (Dictyoneura) mo7iyi, Brong., representing a member of the group 

 Protophasmida?. Handlirsch removed the genus to the group of Palaeodictyoptera 

 incerta3 sedis. 



Scudder was undoubtedly mistaken in referring the wing to the Protophasmida 1 . 

 as a glance at the figure of Protophasma durnasii, Brong., will at once show ('Die 

 Fossilen Insekten,' pi. xvi, figs. 1 — 2). Handlirsch did not see the specimen, and 

 had to base his determination on a sketch of the wing which he considered " con- 

 fusedly drawn." The latter probably accounts for the interpretation which he 

 placed on the various principal veins. More recently I have been able to expose 

 more of the structure, and diagnosed the wing accordingly. If Handlirsch's view 

 were correct, the radial sector would be of enormous proportions, and occupy all 

 the wing-apex. The base of the radius, so far as shewn, is widely divergent from 

 the base of the median — more so, in fact, than at any other part of the whole 

 course of the radius and supposed radial sector. These veins, therefore, have 

 come into union only at the actual point of origin of the wing. This may have 

 been the case, but in my opinion, the radius is wholly simple and undivided, and 

 no radial sector is present. The median and cubitus are large, much divided, 

 and take up the greater part of the wing-area, while the anal veins are few. 



If this view be correct, the wing is a very primitive example of the Protor- 

 thoptera, still retaining evidence in the costa, subcosta and radius, of its 

 Palasodictyopteroid origin. 



