. CLASS I. MAMMALIA: ORDER 1. RODENTIA. 413 
flying-membrane on each side, and using them in the manner of that animal, in gliding from tree 
to tree. It has, however, beneath the base of the tail, which is long and plume-like, a series of 
horny imbricated scales, ten in number, which appear to serve as a defense to the animal as it 
alights upon the trunks of the trees in its leaps or flights. It is lively and graceful in its motions, 
climbs the trunks and branches of trees with dexterity, and launches itself with great precision 
of aim from one tree to another. In the length of its flights it even surpasses the Pteromys. 
Its fur is long, especially on the back; the color is red, spotted with brown; below it is light 
yellow. This animal, whose body is eighteen inches long, and the tail about the same, resembles 
alike the squirrels and the dormouse, but its dentition places it Avith the Hystricidoe. 
Pele's Anomalure, a, Pelei^ resembles the preceding, and is found on the western coast of 
Africa, 
THE BRAZILIAN CTENOMTS. 
THE OTENOMYDES. 
Of this family there are several genera, all South American; some of them climb the trees, 
living, like the dormouse and the squii-rel, upon nuts and fruits. Some run upon the ground, and 
others burrow beneath the soil. They have affinities with both the Chinchilliens and Pseudos- 
tomides. 
Genus CTENOMYS : Ctenomys. — The animals of this genus have a rather long body, ears 
small and nearly hidden in the fur, tail about one-fourth the length of the body. They resemble 
the campagnols, or field-mice, but are of much larger size. 
The Brazilian Ctenomys, C. Brasiliensis, is reddish above and white beneath ; body six inches 
long, the tail two inches. It lives near water, and mines the earth with its numerous galleries. 
It is found in Bolivia, Brazil, and the Argentine Republic. It is common in the sandy valleys of 
the western slope of the Andes, 12,000 feet above the level of the sea. 
The 0. Boliviensis and 0. Nattereri, noticed by some writers, are the same as the preceding. 
The Magellan- Ctenomys, C. Mo.gellanica^ resembles the preceding, and is found in the dry 
sandy plains of Patagonia, where it burrows in the soil so as to make it dangerous for travelers 
on horseback. 
Genus PEPHAGOMYS : Poiphagomys. — Of this there is a single species, the Black Pepha- 
GOMYS, P. Ater : this is five inches long, of a black color, and has nearly naked ears; it feeds 
