MESOZOIC COCKROACHES. 4(J 



j.» 



from the supposition that the oblique veinlets were those of the anal, while they are 

 really those of costal area, the margins of the wing having been interchanged in his con- 

 ception of it. The genus Nethania then might be allowed to drop out of sight, even if 

 it did not appear that the species in question should fall into the same genus as the spe- 

 cies referred by him to Elisama, in the conception of which, as pointed out above, he 

 made an exactty similar error. The species seems in fact to fall next to E. Kneri, hav- 

 ing a very similarly arcuate mediastino-scapular vein, terminating, probably, higher than 

 there, and a similar sweep and manner of forking of the median veins, and, besides, a spot 

 near the base of internomedian area (but farther out than in E. Kneri) apparently made 

 up of numerous cross veins; but the basal sinuation of the main vein is much greater 

 than is possible in E. Kneri and the basal arcuation of both externomedian and inter- 

 nomedian nervules, especially the latter, is so much less marked, so comparatively slight 

 indeed, that it was not at first recognized as a member of this group, of which indeed it 

 must be looked on as a rather aberrant form. 



Length of fragment, 8 mm.; probable length of wing, lO.o mm. The breadth is too 

 uncertain in the figure to give any definite statement. The specimen comes from the 

 middle Purbecks of Durdlestone Bay, England. 



Elisama Kneri. 



PI. 47, fig. 1. 



[Without name] Brodie, Foss. Ins. Engl., 118, PL 5, fig. 1. 



Elisama Kneri Gieb., Ins. Vorw., 320. 



Blattidium Kneri Heer, Viertelj. naturf. Gesellsch. Zurich, ix, 291. 



I have received from Mr. Brodie the original of his illustration, of which I give a new 

 figure showing the wing to be less complete than his plate would lead one to suppose. 

 Only about half the wing remains, but this the most important part, more than a third, 

 probably, of the tip being broken off, and a not unimportant part of the base. The straight, 

 scarcely divergent costal and inner margins of the fragment indicate, with the neura- 

 tion, a form like that restored, which, if correct, would make the wing about two and 

 one-third times longer than broad and broadest just beyond the middle. The medias- 

 tino-scapular vein has a very strong arcuation, strongest on the basal side, since beyond, 

 by successive forks, it loses the strength of its arcuation and is probably carried to the 

 very tip of the wing; the greatest width is before the middle of the wing, where the costal 

 area is considerably more than two-fifths the breadth of the wing; the basal branches are 

 simple and oblique, those beyond forked or compound and increasingly longitudinal. 

 The externomedian branches are all superior, the internomedian all inferior, but all take 

 a common arcuate sweep so as to be longitudinal in the middle of the wing, and the 

 former probably occupy on the margin only the lower half of the tip. Between all the 

 veins which reach the margin are intercalates, and where the internomedian nervules 

 commence to become longitudinal, i. e., just where the lowermost approaches the border, 

 they are obscured by a large roundish fuscous spot, which nearly crosses the entire field. 

 The anal furrow and anal area are lost in the broken base of the wing, but must have 



