464: 
VERTEBRATA. 
ai! ai! whence its name. It is tenacious of life, and will move its legs half an hour after its 
heart and bowels are taken out. There are many varieties of this species, among which is the 
Yellow-faced Sloth, B. gularis. Certain naturalists hold that some of what are called varieties, 
are in fact distinct species. 
THE COLLAEED SLOTH. 
The GiPAKEiou, or Collared Sloth, B. torquatus, has a naked face of a black color; the hair 
is of a less withered look than that of the preceding; the forehead, temples, chin, and breast are 
covered with reddish or rust-colored hair, slightly frizzled ; on the crown of the head it is long 
and yellow, and on the rest of the body, pale orange ; but the most distinguishing mark of the 
species is a large black collar which completely surrounds the neck. Beneath the outer coat 
there is an inner one of very fine fur, which is of a dark brown color on the collar, but gradually 
diminishes in intensity toward the croup, where it is entirely white. In other respects this spe- 
cies resembles the Ai. It is found in Brazil. 
The Burnt-back Sloth, B. ustus^ is chiefly distinguished by a faintish black line running along 
the back, accompanied by a large spot of yellow or orange color on each side. 
THE DASYPIDES, OE AKMADILLOS. 
The name Armadillo was given by the Spaniards, and means clad in armor, which is descrip- 
tive of the bony crust or coat of mail with which these animals are covered. The Portuguese ap- 
plied to them the term Encouherto, which has a similar signification, and is now used as the title 
of one of the genera ; Tatou is the Brazilian name, and is used by French writers instead of Arm- 
adillo. The scientific name Dasyims means hairy-foot, which was one of the old Greek names 
for the hare or rabbit ; it is not descrijDtive of the animal in question, but it has become sanctioned 
by custom, and so its use is continued. 
The Armadillos at first sight appear like reptiles, being of a broad squat form, and covered 
with a sort of bony shell, reminding one of the carapace of the tortoise ; but on examination we 
find that it is not, like that, one connected and solid framework, nor does it extend under the 
belly. It consists of four parts, as follows : first, a buckler covering the head and neck ; second, 
a buckler covering the shoulders and a part of the back ; third, a buckler over the rump ; and 
fourth, a series of broad bands across the loins. The form and relative size of these several parts 
vary in different species, birt this general arrangement is observed in all, with a single exception, 
which we shall hereafter notice. 
The substance of which this armor is composed is of a bony or horny nature, somewhat like 
