213 
distance between the subcostal and marginal cross veins,—points 
more or less related. But it differs from the modern forms of 
Cladura in so many and, as it appears to me, so much more import- 
ant points than do the fossil species here referred to Cladura, that it 
seems more rational to separate it generically from both. 
The points of its distinction from Cladura are the following : 
The preefurca arises at a far earlier point in the wing, at the end of 
the basal third of the same, and though immediately arcuate has 
but a slight basal curve and is thereafter straight, running very near 
to and but slightly divergent from the first longitudinal vein; in 
this respect the fossil species of Cladura agree more nearly with it 
than with the recent species. The subcostal cross vein is at the tip 
of the auxiliary vein, so that its distance from the base of the pre- 
furca is a fourth more than the breadth of the wing. The marginal 
cross vein is In consequence much nearer the subcostal cross vein 
than the tip of the first longitudinal vein, and the petiole of the 
first submarginal cell is a little longer than the interval between the 
two cross veins. Moreover, the branch of the second longitudinal 
vein through which the first submarginal cell originates is straight 
throughout and not, as in the modern species of Cladura, strongly 
arcuate basally ; in this particular again the fossil species of Cladura 
agree rather with Cladoneura. The third and not the second pos- 
terior cell is petiolate. The anterior branch of the fourth longi- 
tudinal vein arises at a small angle (and not at nearly or quite a 
right angle) from the main stem, so that the proximal end of the 
discal cell is pointed and not brcad. Finally, the great cross vein 
lies much nearer the margin of the wing, striking the discal cell 
opposite the origin of the posterior branch of the fourth longi- 
tudinal vein. In addition, the legs, which are very imperfectly 
known in the single specimen preserved, appear to be much shorter 
than in the fossil species of Cladura, the hind femora being but 
about half as long as the wings, while in the latter they are fully 
two thirds as long. The wings are but little more than three times 
as long as broad, with rather full posterior margin. 
A single species is known. 
Cladoneura willistoni. 
Pl. 4, fig. 2. 
Wings a little more than three times as long as broad, immacu- 
late, without stigma, very feebly infumate. The auxiliary vein 
