LETHITES REYNESII Scudder.
[Plate I], figs. 2, 5.
Satyrites Reynesii Scudd., Rev. et. Mag. de Zool., 1871-72, 66-72, pl. vii (1872); Ib., Descr. Pap. Foss. 1-7, pl. (1872); Ib., Geol. Mag. ix, 532-33, pl. xiii, figs. 2, 3 (1872); Ib., Descr. Foss. Butt. 1-2, pl., figs. 2, 3 (1872); Brod., Distr. Corr. Foss. Ins. [Satyrites Reynesii], 8-9 (1873).
I give below the original of the first paper cited above, excepting the portion which was quoted under the genus.
In a recent examination of the rich collection of fossil insects from Aix, preserved in the Museum of the city of Marseilles, my attention was attracted by two little slabs containing the traces of a fossil butterfly. Although by no means so well preserved, nor so perfect as the remains of a butterfly from the same beds, described by Dr. Boisduval more than thirty years ago, a glance showed that it could not be referred to that species, since the costal nervure of the fore wings was greatly swollen. No such form having to my knowledge been described from these beds, Dr. Reynès, the accomplished director of the establishment, courteously placed the best specimen in my hands for closer study; and from it the following account and illustrations have been drawn. The second specimen is very imperfectly preserved, but since it exhibits in all its features an exact resemblance to similar parts in the better specimen it undoubtedly belongs to the same species.
The fossil ([Pl. I], fig. 2) is a natural cast of a butterfly lying upon its side, the wings folded back to back, the legs extended as if hanging, the tongue uncurled and, with the antennæ, drooping in a direction similar to that of the legs. The right fore wing, which lies beneath, is pushed a little outward and also forward, even at its base, showing that the specimen must have been greatly macerated in very quiet water, before being covered by the deposits which have preserved its more essential features. The condition and position of all the parts also lead us to conjecture that it was swept into its final resting place by a gentle current, which left the slighter appendages lying in the direction of its final action.
It is evident that the object is a cast, for the veins of the wing which lie uppermost on the stone are impressed as we see them on the upper surface of the wings of living Oreades, while those of the wing lying beneath (veins which are plainly covered by the impressed nervures where the two come in contact) are in relief, as seen on the under surface of the same butterflies; that is, we have here the reverse of what would be the case, were we examining a living butterfly in this position.
The parts before us are: a poorly preserved body, vague indications of the terminal palpal joint, an antenna (probably a portion only), an unrolled tongue, the hinder pair of legs and portions of the other pairs, the greater part of the two front wings and fragments of the base of the hind wings. Of the latter, no border remains and only the base of a few of the nervules, which give scarcely any additional information as to the pterology of the insect. The only portion of the margin of the front wings which can be determined with certainty is the most essential part, the apex and the upper half of the outer border of the left wing, enough to show that its general contour was similar to that of the European Satyrids of the present epoch; but throughout the remainder all the nervules can be exactly traced. This being then the best preserved portion of the insect, we will consider its structure in detail, subsequently adding whatever can be gleaned from the examination of the other parts.[Q] [The account of the structural framework of the wing is given under the genus].
The basal two-thirds of the wing appears to have been more darkly clouded than the other portions, although in this fuscous area there is apparently a clearer space towards the upper, outer portion of the cell. There is also a distinct, darker, uniform and equal rounded spot in the middle of the outer two-thirds of the lowest subcostal interspace, nearly reaching the nervule on either side; in the specimen it appears to be broader than long by encroaching upon the next interspace in front, but this is evidently only apparent, the spots of the two wings (one of which I have stated to be a little in advance of the other) being blended. The object is so well preserved that one can see throughout the parallel series of minute punctures forming the points of insertion for the scales, outlines of the latter of which I have failed to discover. The wing is 28·5mm. long, the tip of the cell being distant 15mm. from the base of the wing; the costal nervure is inflated for a distance of 6·5mm., and the extreme width of this portion is 1mm.; the rows of punctures indicating the former insertion of the scales are ·12mm. apart.
Of the body itself nothing can be predicated, unless it be that the form of the abdomen and the appearance of its tip lead us to conjecture that the specimen was a female which had deposited most of her eggs, or in which they were but partially developed.