so FOSSIL TXSECTS OF THE BRITISH COAL MEASURES. 



the lirst branch of the iiit.'(li;iii, 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 lirancli which 

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

 twigs before reaching the inner margin. The second of these twigs forks, A 

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

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

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

 arose may have arisen. a> 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 fairlv parallel with the 

 first along its whole length, giving off, as it does so, four inwardly directed t \\ igs, 

 of winch 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 (Dicti/oneura) ntu/ti/i, Brong., representing a member of the group 

 Protophasmidse. Handlirsch removed the genus to the group of Palaeodictyoptera 

 incertaa sedis. 



Scudder was undoubtedly mistaken in referring I he wing to the Protophasmidse, 

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

 h'ossilen 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 lie 

 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 enormou> proportions, and occupy all 

 the wing-apex. The base of the radius, so f;ir as shown, is widelv divergent troin 

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

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

 come into union onlv at (lie actual point of origin of the wing. This may have 

 been the case, but in my opinion, the radius is whollv 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 lew. 



If this view be correct, the wing is a verv primitive example ol the Protor- 

 thoptera, still retaining evidence in the cosla. Mibcosla and radius, ol its 

 I ';ihe' ii lid vi ipi eroid origin. 



