In the upper Eocene (Uinta stage) there were at least two kinds of camels, the time-relations of which to each other are not known, that is, whether they were contemporary or successive. The best-known genus, _†Protylopus_, may perhaps not be in the direct line of camel descent, but it so nearly represents the proper ancestral stage that, for all practical purposes, it will serve nearly as well. It was a much smaller animal than the smallest of the White River species, and was hardly larger than a “jack-rabbit.” The teeth of each jaw were in continuous series and the canines were but slightly longer than the incisors; the premolars had less antero-posterior extension than in _†Poëbrotherium_, and all the molars above and below were very low-crowned. The skull was almost a miniature copy of that of _†Poëbrotherium_, but more primitive in a number of details, the most important of which was that the tympanic bullæ were much smaller and hollow, not filled with spongy bone. The neck, concerning which it would be very desirable to have information, is almost the only part of the skeleton that is not known. The fore limb was considerably shorter than the hind, making the back slope downward from the rump to the shoulders; in the fore-arm the two bones were entirely separate and in the lower leg the fibula, though very slender, was still complete. In the manus there were four functional digits, the laterals not very much smaller than the median pair; but in the pes the lateral metatarsals were reduced to mere bony threads, to which small phalanges, in full complement, were attached, making tiny dew-claws. With _†Protylopus_ ends the genealogy of the camels so far as it can be definitively traced, but in the middle of the Bridger stage is found a genus, _†Homacodon_ (family †Dichobunidæ), which is a probable member of the series. However, until the connecting link can be found in the upper Bridger, this conclusion cannot be demonstrated and _†Homacodon_ itself is incompletely known. It was a very small animal, even less in size than _†Protylopus_, and had not yet acquired the selenodont molars. These teeth were quadritubercular, _i.e._ with four principal cusps arranged, in the upper molars, in a square, and with a minute cuspule between each transverse pair, while the lower molars were narrower and had only the four principal cusps. The cusps were not conical, as they are in the pigs, but angular and pyramidal, the first step toward the assumption of the selenodont form. The skull was not specifically cameline in appearance, but rather indifferent, as though almost any kind of an artiodactyl might have been derived from it. The feet were decidedly more primitive than those of the Uinta genus, having four functional digits each, perhaps five in the manus. While it cannot be positively stated that _†Homacodon_ was the actual ancestor of _†Protylopus_, it nearly represents what we should expect that ancestor to be.