Yukon River, and from various parts of British America. P. cardui has its range more to the southward, and abounds in Arizona and New Mexico, where antiopa is but occasional. The larvæ of both species are gregarious, those of antiopa feeding on willow, of cardui principally on thistle.

13. Aglais milberti, Godart.

A few specimens of this were taken at Chief Mountain, August 22. The species ranges eastward to the Atlantic, but is nowhere common. In Colorado, Mr. Mead found it abundant, and saw large numbers of the larvæ, which are gregarious and feed on willow. Probably this species is more abundant in the Rocky Mountains than elsewhere. I have not received it from States to the south of Colorado, but in British America it is found as far north as Fort Simpson on the Mackenzie River.

No other Vanessans were taken, but doubtless j-album and huntera are also common on the forty-ninth parallel. Grapta faunus and progne may also be found, and perhaps zephyrus and satyrus.

No species of Limenitis were taken, though doubtless one or more species would have been abundant earlier in the season; arthemis, and its supposed dimorphic variety proserpina, and weidemeyeri, the latter ranging over the mountains from Arizona to Montana, and arthemis to the northward as far as Fort Simpson.

SATYRIDE.

14. Cœnonympha ochracea, Edwards. 15. Canonympha inornata, Edwards.

The former light ochre-yellow, the other dark brown, changing to umber. Several specimens from different localities were taken. These are small butterflies, expanding about one inch, and inhabit the Plains, their larvæ feeding on the blades of grasses. Species of this genus abound in all the valleys of the Rocky Mountains, and to the westward as far as the Pacific, but to the eastward are unknown.

16. Satyrus boöpis, Behr.

Chief Mountain, July 21. Represented by a single specimen. This species belongs rather to Oregon and British Columbia, being apparently very rarely found in the Rocky Mountains. I have not seen it from Colorado, and but once or twice in Dr. Hayden's collections from Montana. It is one of our largest species, size of alope, and is without the yellow band in fore wings seen in that species, and usually has no ocelli on the under side of the hind wings.

17. Satyrus charon, Edwards.

A few specimens were taken at Frenchman's River and Chief Mountain. This is a small, black species, first noticed by Mr. Mead in Colorado,

where it is common, and afterward by Dr. Hayden in Montana, and seems to be limited to the mountains in its range.

The larger Satyrida frequent open forests as well as grassy plains, their larvæ living on the grasses.

LYCENIDE.

18. Thecla mopsus, Boisduval.

This genus was represented by a single specimen of mopsus, a species which is spread over the northern parts of the continent, and on the Atlantic as far south as Georgia.

19. Chrysophanus rubidus, Edwards.

A single specimen was taken near Three Buttes, August 8. The species seems limited to Montana and westward to Oregon. Dr. Hayden has sent an occasional specimen from Montana. It is of a fiery copper color, and forms one of a group of three, the others being sirius from Colorado and cupreus from Oregon.

20. Lycana melissa, Edwards.

A number of specimens were taken at several localities. The species ranges from Arizona to British America.

No other Lycanida were taken, though doubtless Lycana is numerously represented on the forty-ninth parallel, and of Thecla and Chrysophanus three or four species of each should be common. These insects likewise inhabit grassy plains and slopes, and the Theclas open forests.

HESPERIDE.

21. Pyrgus tessellata, Scudder.

A species spread over the greater part of the continent, usually known as sileus.

22. Pamphila colorado, Scudder.

Allied to comma of Europe, and common throughout the Rocky Mountains.

The Hesperida are very numerously represented in the United States, and comprise nearly one-fourth of all the species of diurnal Lepidoptera within our limits. From the Rocky Mountains and west to the Pacific, the species are much less numerous than in the eastern and southern districts.

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ART. XXIV.-AN ACCOUNT OF SOME INSECTS OF UNUSUAL INTEREST FROM THE TERTIARY ROCKS OF COLORADO AND WYOMING.

BY SAMUEL H. SCUDDER.

An examination of an extensive series of fossil insects recently obtained in different parts of the Rocky Mountain region has brought to light a large number of remarkable forms. To illustrate this, and as an indication of what we may expect further researches will reveal, I have brought together in this paper a few examples from different orders. These, however, are some of the most striking. It will scarcely fail of remark that those which come from the Florissant beds indicate a tropical relationship to a conspicuous degree. Perhaps this selection may show it to a far greater extent than a more systematic one would do; but my studies are constantly revealing similar affinities, leaving no doubt in my mind that the faunal elements of Tropical America of to-day entered largely into the insect-life of the central United States in Tertiary times. Similar tropical characteristics have already appeared in other Tertiary insects I have examined, such as in the Orthoptera previously described from Florissant, the Entimus, the Aphana, and perhaps the Cyttaromyia from White River, and possibly also the Lithortalis from British Columbia.

The beetle described below (Parolamia rudis), however, is of an Old World rather than a New World type.

Perhaps the most generally interesting insect will be thought to be the fossil butterfly (Prodryas persephone), which is so perfect as to allow description of the scales, and, besides being the first found in America, is far finer than any of the nine specimens which have been discovered in Europe, and shows, moreover, some features betokening its antiquity. The fly (Palembolus florigerus) is interesting, not only as representing a highly specialized type hitherto unknown on this continent, but as showing how the semblance of an original vein may be formed in the wings out of mere fragments of distinct veins, affording, indeed, a better example of this feature than living members of the same group in other parts of the world.

The insects from other places than Florissant are described on account of their remarkable character. The eggs of the Corydalites are, so far as I know, the first insect-eggs that have been found in a fossil state; but aside from that, they have an intrinsic interest. The Dysagrion from Green River is of a marked tropical type; while the cases of the caddisfly enable me to draw the attention of collectors to the occurrence of such objects in a fossil condition.

LEPIDOPTERA: PRODRYAS (apó, ôpias).

A stout-bodied, strong-winged genus of Præfecti. Eyes moderately large. Antennæ remarkably short, scarcely longer than the head and thorax together, the club moderately long, obovate or subfusiform, about twice as stout as the stalk, about five times as long as broad, broadly and regularly rounded at the tip, and composed of eleven or twelve joints of nearly equal length. Palpi extending beyond the front of the head by a little more than the length of the apical joint; the latter about five times as long as broad, equal, cylindrical, broadly rounded at the tip, and uniformly clothed with slender scales; the middle joint appears to be moderately slender and compressed, twice as broad as the apical joint.

The thorax is stout, with the general form of the Præfecti, and particularly of the special group to which Vanessa and Hypanartia belong. The median ridge of the mesothorax has a minutely impressed line posteriorly; the scutellum is pretty large, lozenge-shaped, slightly broader than long; the metathoracic epimera are pretty large, and taper apically at the median line of the thorax to a blunt point. The legs are too imperfectly seen through the wings to give even the length of any part or of the whole of any one with probability. Posterior lobe of patagia about twice as long as its mean breadth, curving outward and tapering regularly and rapidly to a somewhat produced outer apical angle.

Fore wings nearly twice as long as broad, unusually triangular, the costal margin almost exactly straight, but bent with a posterior curve at the extremity, and slightly convex at the extreme base; the outer margin is also nearly straight on either of its two halves, separated by a slight bend at the extremity of the upper median nervule, the lower half faintly convex; the inner margin is straight, the outer angle only a little rounded. The costal nervule terminates at the middle of the wing. The first superior subcostal nervule originates shortly before the origin of the first inferior subcostal nervule, and terminates scarcely beyond the middle of the third quarter of the wing; the second superior and second inferior subcostal nervules originate in the middle of the wing, the latter from the first inferior branch, as far beyond its base as the first superior nervule before it; the former terminates at the middle of the outer half of the costal border; the latter diverges from the first inferior branch so slightly as to be nearly continuous with its basal portion; the third superior branch originates as far beyond the second as the second beyond the first, and the fourth midway between the third and the outer margin; the latter is widely parted from the main vein, and strikes the costal margin as far beyond the obtuse but distinctly angled apex of the wing as the main branch passes below it. The cell is open. The first median branch originates midway between the base and the final forks, and the latter diverge very slightly at base, leaving a very open and broad subcosto-median interspace.