DR. RITRMEISTER ON THE MAMMALS OF LA PLATA. 
393 
shall see by reference to the “ Systematische Uebersicht,” produces 
no less than 14 members of the same group. 
Of Rodents, every where numerous, alike in species and indi¬ 
viduals, only 13 species, the whole of which belong without exception 
to forms peculiar to the Neotropical Region, were collected by Dr. 
Burmeister in La Plata. But as Mr. Darwin obtained 10 species of 
the family Muridce alone in the same country, it is obvious that 
many of the smaller species must have escaped Dr. Burmeister’s 
researches. The Reithrodon typicus and four species of Hesperomys 
were the only Mice obtained by our author. The Coypu Rat ( Myo - 
potamus coy pus), Ctenomys brasiliensis, the Yizcacha, one of the 
most characteristic animals of the South American Pampas, the 
allied Rock-Viscacha (Lagidium cuvieri), and three Cavies ( Dolichotis 
patuchonicu, Cavia leucopyga and Anoema leucoblephara , n. sp.) with 
the Capybara ( Hydrochoerus capybard) complete the series of Rodents 
met with by Dr. Burmeister in La Plata. 
We now come to the most eminently characteristic group of 
South American Mammals—the Edentates. The descendants of the 
gigantic animals of this Order, which peopled the continent in bygone 
ages, exist at the present time only in the few members of three very 
distinct families : the Sloths ( Rradypus ), the Armadillos (Rasypus), 
and the Anteaters (JKyrmecophaga). No Sloth nor Anteater was 
obtained by Dr. Burmeister in La Plata, though MyrmecopJiaga 
is stated to occur in the northern wooded districts. The Rasypo- 
didce, however, are represented by five species, all distinct from those 
of South-Eastern Brazil as enumerated in the “ Systematische Ueber- 
sicht.” Thus we find 
In Paraguay. 
D. (Eupliractus) villosus. 
- minutus. 
D. (Tolypeutes) conurus. 
D. ( Praopus) hybridus. 
ChlamypJiorus truncatus. 
We believe that the species of this group will be found to be for the 
most part very local, and that the great confusion, which, in spite of the 
labours of several distinguished Naturalists, still prevails among them, 
is mainly attributable to the fact of the study of their geographical 
distribution having been so much neglected. That extraordinary little 
animal-the Pichyciego or Blind Armadillo of the natives ( Chlamydo - 
pkorus truncatus),* which is often said to be found in Chili, is entirely 
* In a recent part of the Transactions of the Nat. Hist. Society of Halle, 
Dr. Burmeister, who is now, we believe, resident in Buenos Ayres, has described 
a second species of this curious form from the environs of Sta. Cruz de la Sierra 
in Bolivia, which he proposes, to call Chlamydophorus retusus. See Abh. d. Nat. 
Gesellschaft zu Halle, Bd. vii. 
In Brazil. 
D. (JPriodontes) gig as. 
D. (Xenurus) Vl-cinctus. 
D. „ hispidus. 
D. (Rup hr actus) VI. cinctus. 
D. (Tolypeutes) tricinctus. 
D. (Rraopus) longicaudus. 
