370 TROPICAL AMERICA AND ITS ANIMALS 



Brazilian tree-porcupine (Synetheres prehensilis), of Brazil, Guiana, and part of 

 Bolivia. A second is the long-haired Mexican porcupine (S. novce-hispanice), 

 which looks, when in repose, like a knot of a lichen-covered branch. The bristle- 

 spined porcupine (Chcetomys subspinosus) of central and northern Brazil, is rather 

 larger than either of the preceding, from which it is distinguished by its bristle- 

 like spines, the absence of prehensile power in the tail, and the fact that it is not 

 exclusively arboreal in its habits. Coendou, the native name of the Brazilian tree- 

 porcupine, has of late years been adopted as the name of the genus, in place of 

 Synetheres. 



Another family of rodents, whose distribution is confined to 

 Africa, the West Indies, and Central and South America, is typified 

 by the degu (Octodon degus), a species resembling a rat in size and general appear- 

 ance, but with a shorter tail, tufted at the tip and often bent backwards in squirrel- 

 fashion. The degu, which is a good climber, and stores up provisions like a 

 squirrel, inhabits Peru and Chile, other species of the group being found in Chile 

 and Bolivia. A Bolivian species has been described as Octodontomys, or Neoctodon. 

 The members of the allied genus Aconcemys are found in parts of the southern 

 Andes, which are covered with snow for several months of the } T ear. 



In the sandy districts of the Ai-gentine pampas may be heard all day and all 

 night the ringing cry of a member of the same group, which in large numbers leads 

 a subterranean life. The sound of the tuco-tuco, as the animal is called, much 

 resembles the blows of a hammer, first strong and measured, then lighter and in 

 quicker succession. Tuco-tucos burrow long passages at no great depth beneath 

 the ground, their course being marked by small mounds on the surface. The red 

 incisor teeth of these rodents are very broad, and the fore-feet have long curved 

 claws. There are several species, of which Ctenomys brasiliensis is confined to 

 Brazil, while C. magellanica is restricted to southern Patagonia. To the same 

 group belongs the genus Habrocoma, which, like the preceding and the following, 

 is exclusively confined to Central and South America. The coypu (Myopotamus 

 coypw), inhabiting both sides of the Andes from Peru southwards, resembles a 

 beaver in general appearance and habits, living on the banks of rivers and lakes, 

 and feeding on the leaves, roots, and seeds of aquatic plants. In the banks of its 

 native rivers it forms burrows, consisting of a passage some 3 or 4 feet long ending 

 in a chamber 2 feet in diameter ; but when the bank is not high enough to admit 

 of this, the eoypu builds a fiat nest among reeds and rushes. The coypu seems to 

 accommodate itself to different conditions according to locality. In the Chonos 

 Archipelago, for instance, where it lives exclusively in the bays among the small 

 islands of the group, and where it is said to feed partly on molluscs, it establishes 

 itself in the forest at some distance from the water. Again, in parts of Argentina, 

 where it was formerly dying out in consequence of constant pursuit, but began to 

 increase when its destruction was prohibited, it is said to have forsaken an aquatic 

 life and become a migratory land-animal, till it was almost exterminated by an 

 epidemic. In Argentina it is known as nutria, under which name its fur is an 

 important article of commerce. 



To another section of the same family belong the spiny rats of the genera 

 Dactylomys, Loncheres, Echinomys, etc., all of which are long-tailed rodents, with 



