378 VIEW OF THE FAUNA OF BRAZIL 



glance or longer examination have satisfied me to be different 

 from the recent. These species are seventeen, viz. the 

 gigantic Ant-bear, the four species of Peccari, the large 

 Tiger, Cynailiirus, the Cave-wolf, the Cave-jackall, the 

 Honey -glutton [Eyrara), the largest species of Spiny -rat, 

 the large Cuandii [Hystrix prehensilis), the gigantic Cutia, 

 the three species of Paca, and lastly, the gigantic Capivar. 

 Adding now these seventeen species to the seventeen before 

 described, we have thirty -four out of forty that are decidedly 

 different from existing species. The second division of the 

 fossil species is composed of those which, from the more or 

 less considerable portions that I possess of their skeletons, 

 show so great a conformity to the living species, that I have 

 not been able to discover any specific difference. These are 

 the following six : one species of genus Dasypus, two spe- 

 cies of Echimys, the fossil Rabbit, the Perea, and a fossil 

 species of Cutia, Thus the proportion of the conformable 

 to the unconformable species is as 6 to 34. 



In this manner we have seen, as we gradually descend in 

 our comparison of orders, families, genera, and down to spe- 

 cies, that at each step the unconformity between the ancient 

 and present fauna increases. This difference, indeed, is so 

 great in the last step of all, that one may well be tempted to 

 propose tlie question, whether this slight bond of connexion 

 wherewith we see them linked together, is really fashioned 

 by nature herself, or is only attributable to our imperfect 

 methods and means of comparison. The decision of this 

 question being of the highest importance to science, the 

 Society will allow me to dwell a little longer on the subject. 

 I would wish first to remark, that the conclusion on which 

 the identity of the six species with the existing fauna is 

 founded, is far from possessing the certainty of that which 

 determines the unconformity of the other thirty-four. I do 

 not possess a perfect skeleton of any one of these six species ; 

 and it is very possible that these fossil species, though agree- 

 ing with the recent in those portions that I possess, might 

 differ from them in others, with which I am not acquainted. 

 This possibility has, in fact, been proved in the case of one of 

 the extinct genera, the Paca. I had in my possession a vast 

 quantity of the remains of this genus, which showed so 

 striking a resemblance to the living species, that I at first 

 referred the fossil animal to it, until the examination of the 

 respective skulls, as I have before observed, convinced me 

 not only of their specific difference, but also proved to me 

 the existence of two distinct species among the fossils of this 

 genus. If, therefore, we were to allow analogy to be our 



