It was necessary, therefore, to examine further. In so doing, he found thirteen ribs, and as many dorsal vertebra, with six very long lumbar ones that filled the space of six of the dorsal. The sacral vertebra, together with the first that belonged to the tail, possessed very large trans verse apophyses; the radius and ulna were distinct, and capable of moving easily upon each other ; the fibula was separate from the tibia, with a thin enlarged head, and the scapula nearly similar. Thus it was found to re semble, in all important particulars, the Sarigue, and es pecially the Didelphis murina, with which it was compar ed ; and that resemblance was afterwards completely con firmed, by finding that it possessed what are called the marsupial bones ; two long and flat bones, namely, that are articulated upon the anterior edge of the pubis, and serve to support the pouch, so characteristic of this tribe.
It still remained to know whether this Didelphis be longed to the Sarigue or the Dasyure. In the latter there are four toes, nearly equal, the large one being so short that the skin nearly hides it, so that it appears only like a tubercle ; but in the Sarigue this toe is long and well marked, the others being unequal, and the little toe, par ticularly with respect to its metacarpal bone, being shorter than the others. In these points the fossil bones were found to agree; so that the question was at length decid ed, as to the discovery of a fossil animal of a genus now only known in America.
It was next necessary to determine whether this wa...
tiso a living species ; but as all these are not accurately known, it could only be determined that this approached nearest to the Didelphis murina, from which, however, it still differed in many Important particulars, some parts being proportionally larger, and others sm tiler. Thus, for want of more conviction of its actual existence, it was considered an extinct species, and named Didelphis Pa risiensis.
We shall now mention the few circumstances which led to the discovery of the Canis, and other obscure species, as they will convey an idea, not only of the diffi culty of these investigations, and of the methods pursued, but also of the value of the evidence On these subjects.
A jaw had been found in the gypscous strata, which was thought at first sight to resemble either that of a dog or of a fox. The condyloid apophysis was highly elevat ed, the notch in the posterior edge formed an arc of a circle, the posterior angle was hooked, and the grinding teeth were toothed, triangular, and cutting Hence it was obvious that it was a carnivorous animal, while the shape of the grinders also proved that it must have belonged to the genus Canis. It was found, indeed, that the jaw
agreed in every respect with those of that genus ; and hence, as nothing more could be disco% ered belonging to this species, it was placed provisionally in this genus by the name of Canis Parisiensis, as we have already men tioned.
An astragalus of some carnivorous animal was also found; but as it was too small to suit this jaw, and has not been adapted to any of the animals yet found in the same place, it remains unassigned.
A fragment only of a lower jaw was also found, but of a nature different from the preceding of the supposed Canis. It contained one complete tooth, and the fragment of an other. It appeared to have remained at first undetermin ed whether it should be referred to the genus Canis or not; but if we understand right, it was thought more likely to have belonged to some carnivorous animal of a nature between that genus and the Viverra, having an analogy to the Viverra genetta and to the ichneumon.
The lower extremity of an os humeri was the source of much difficulty. It was thought to have belonged to a species of martin of about the size of the common cat. It was not possible to associate it decidedly with the jaw above mentioned ; but Cuvier remarks that if they did be long to the same animal, it must have been one that would have formed a genus entirely distinct from that of any carnivorous animal yet known. A small astragalus which was found, and which somewhat resembled that of a cat or ichneumon, was thought to belong to this humerus.
An ulna was also found, which was thought from its form to be that of some carnivorous animal, and of those which are possessed of short legs, such as the otter. But if this was the case; the animal to which it belonged must have been larger than the sea otter, even estimating by the largest of those that are known. Being unable to refer it to any known animal, lie considers it as belonging to some creature with which we have at present DO acquaintance.
In the same place was found a metacarpal bone. In re spect to its thickness, this agreed with the same bones in the cats, in the ichneumons, and in the otters. Cuvier preferred placing it with the last, and supposes that it had belonged to the ulna above described; and from its being double the size of the analogous bones in the common otters. he was still farther led to believe that it had belong ed to the same animal as this doubtful ulna.