It was probably Mr. Butler’s want of familiarity with fossils that led him to overlook several features which can be seen in these originals. Having first traced the outline of the wing and the general course of the veins directly from the specimens, I subsequently filled in by measurement all the other parts which I could follow, studying each vein, or supposed vein, with the utmost care, from one end to the other of its course. The result of that study is presented in fig. 8, which differs essentially in its details from the illustrations given by Butler, and looks, as he himself confesses, “exceedingly anti-lepidopterous.” In the first place, the wing is much narrower than depicted by him; and at the extremity of a vein (the submedian vein of Butler’s sketch) there is a slight but decided bending inward of the membrane, as very frequently occurs at the line of demarcation between the middle and inner area of the wing in all or nearly all the lower suborders of insects, but never, so far as I am aware, in Lepidoptera. What he has given as a simple costal vein is neither swollen at the base nor simple, but has two inferior branches near the middle of the wing, united near their origin by an oblique cross vein. Branching of the costal vein is unknown in Lepidoptera; but if it should be claimed that this might be the subcostal, just as much difficulty will be encountered with the structure and relationship of the veinlets below, which must then be considered as belonging to the median vein; in no Lepidoptera can any such irregularity be shown, nor so disproportionate a magnitude of the area covered by the median nervure and its branches; a branched internal vein and cross-veins, which probably united all the longitudinal nervures at no great distance from the outer border (but which can only be certainly predicated for the lower three median interspaces), place this insect wholly beyond the pale of the Lepidoptera. It is but fair to say that Mr. Butler, having examined the original after he had in his possession a tracing of fig. 8, denies the existence of the cross-veins; there is one point, however, which an unprejudiced examination of the fossil cannot fail to show; that Butler’s “fourth branch” of the subcostal[BE] arises not from his third branch, but from his upper discoidal vein; if he can reconcile either this or the points already referred to (on the supposition that his sketch is otherwise an accurate one) with the neuration of any group of butterflies, the writer will be the first to acknowledge it.