“This cat was given me by an old Portuguese priest, who had hunted it down in a thick forest with a small pack of dogs, after a severe chase. It was killed near the Gavia mountain, at the distance of a few miles only from Rio de Janeiro, where it was considered uncommon.” D. Although small, compared with the Puma, (_Felis concolor_, Auct.), this cat, in its slender lengthened body, small head, long tail, and stout limbs, decidedly evinces an affinity to that species. According to the dimensions of the Yagouaroundi given by Azara, Desmarest, and Temminck, it appears that the tail is considerably shorter in proportion in the specimens examined by those naturalists, than in the present individual, and the difference was such, as to induce Mr. Martin to believe that the latter was a distinct species; he accordingly proposed for it the specific name of _Darwinii_. At the time that Mr. Martin described the specimen alluded to, I was also inclined to believe it was a distinct species. I mention this because I am afraid my opinion had a slight share in influencing Mr. Martin’s determination. I have since seen many specimens, and upon comparing their dimensions, I find that the proportionate length of the tail varies more than is usual in other species of cats, and that the difference in the length in this member is not combined with any other distinguishing character. In colouring there is also a considerable variation, some specimens being almost black, and having the hairs but obscurely annulated with white; in others, the hairs are more distinctly annulated, and the head assumes a grayish hue. Others again, are brown, or black brown, having the hairs annulated with yellow. The following are the dimensions of two specimens in the Paris museum, and those given by the authors above alluded to.[11] _Paris M._ _Paris M._ _Desmarest._ _Temminck._ _Azara._ In. Lines. In. Lines. In. Lines. In. Lines. In. Lines. Length from nose to root of tail 30 6 28 0 23 0 30 0 36 9 of tail 24 0 17 0 13 9 22 0 13 9 2. FELIS PAJEROS. PLATE IX. Chat Pampa, _Azara_, Essais sur l’histoire Naturelle des Quadrupèdes du Paraguay. Traduct. Franç. tom. 1. p. 179. Felis Pajeros, _Desmarest_, Mammologie, p. 231. _F. vellere longissimo, flavescenti-griseo, fasciis flavescenti-fuscis indistinctè et sublongitudinalitèr notato; pedibus annulis latis nigris; abdomine maculis magnis nigris; mento albo; caudâ brevi; auribus mediocribus, ad apicem externum nigris._ DESCRIPTION.—The Pampas cat is about equal in size to the common wild cat of Europe (_Felis Catus_, Linn.). It is however of a stouter form than that animal, the head is smaller, and the tail is shorter.