1865.] 



Sclater on the Mammals of South America. 



615 



Eegion, and therefore especially characteristic of this Fauna, being 

 printed in italics : — 



Canid.^:. 



Felid^:. 



MusTELnxaE. 



Unsnxra. 



Icticyon 

 Canis 



Felis 



Mustela 

 Galictis. 

 Lutra 

 Mephitis 



TJrsus 

 Procyon 

 Nasua 

 Cercoleptes 



The Eodentia, which now claim our attention, in South America, 

 as in nearly every other part of the world, are more numerous in 

 species, and more abundant in individuals, than any other order 

 of Mammals. A considerable number of genera belonging to this 

 group are also peculiar to the Neotropical Eegion, especially, as we 

 shall see, among the Hystricine forms, which are very extensively 

 developed in this part of the world. In attempting to give an outline 

 of the more noticeable features of this difficult group, I shall base my 

 remarks principally upon Mr. Waterhouse's paper on the distribution 

 of this Order, given in the Zoological Society's ' Proceedings ' for 

 1839, and in the same author's volume on the Leporidse and Hystri- 

 cidfe in his excellent (but, alas ! unfinished) ' History of Mammals.' 

 In the above-named paper of Mr. Waterhouse, the Eodentia are 

 divided into eight families. In the tables subsequently given in 

 Keith Johnston's ' Physical Atlas ' only four of these are adopted, 

 namely — Sciuridse, Muridaa, Hystricidaa, and Leporidaa. To these 

 I agree with Professor Baird in adding, as a distinct family, the 

 SaccomyidaB or Pouched Eats, distinguished by their large and distinct 

 external cheek-pouches, a group peculiar to, and very characteristic of, 

 the Northern Eegion of the New World, which may be intercalated 

 between the Muridse and Sciuridse. 



The Sciuridee, which must be placed at the head of the Eodentia, 

 are by no means abundant in South America. Of five well-marked 

 genera — Sciurus, Pteromys, Tamias, Spermophilus, and Arctomys, com- 

 monly referred to this family, but one— typical Sciurus — occurs at 

 all within the limits of the Neotropical Eegion. And of Sciurus, out 

 of some sixty or seventy known species, seven or eight only are South 

 American. In S.E. Brazil the only species mentioned by Burmeister 

 are Sciurus langsdorfii of the interior and S. wstuans, which is common 

 all along the forests of the eastern coast. The latter Squirrel is alone 

 attributed to Guiana by Schomburgk. In Eastern Peru, besides this 

 two others occur, according to Tschudi, and a fourth (Sciurus strami- 

 neus) has been obtained from the western coast-region of the same 

 country. In the Amazon Valley several others are met with, speci- 

 mens of which were first obtained by the indefatigable collector Johann 

 Natterer. No squirrel is given by Eengger or Azara as occurring in 

 Paraguay, so that we may take the southern limits of this form as 

 terminating with the forest region of Brazil. In Central America, on 

 the other hand, as we go north, the species become more numerous, 

 four Sciuri having been obtained in Guatemala by Mr. Salvin, and 

 several others occurring in Southern Mexico. 



