142 MAMMALIA. 
and the little toe, reduced to small rudiments, are hidden under the 
skin, and soldered to the metatarsus and metacarpus; the clavicle, 
also reduced to a rudiment, is firmly united in the acromion. The 
arms are double the length of the legs; the hair on the head, back, 
and limbs, is long, coarse, and inelastic, something like dried hay, 
which gives it a hideous aspect. Its colour is grey, the back beg 
frequently spotted with white and brown. It is as large as a Cat, 
and is the only mammiferous animal known which has nine cervical 
vertebra. 
There is an Ai called the Burned Back Ai, from the circumstance 
of having between the shoulders a black spot, surrounded with fawn 
colour; but, according to Temminck, it is only a variety; the ap- 
pearance alluded to resulting from the wearing away of the long hair 
on the shoulder. The Black Collared Ai, however,—Brad. tor- 
quatus, Geoff. Ann. Mus., Schreb. LXXIV, A, is a species that is 
very distinct, even in the bony structure of the head. 
M. Fr. Cuvier applies the name of Brapypus to those species only 
which have two nails to the fore feet, the Cuotapus, lig. Their ca- 
nines are larger and more pointed, and they are wholly destitute of a tail. 
There is but one known, 
B. didactylus, L.; Buff. XIII, i. (The Unau). Which is. 
somewhat less unfortunately organized than the Ai. Its arms are 
not so long, and its clavicles are complete; there are fewer bones of 
the feet and hands which become soldered together; the muzzle is 
more elongated, &c. It is larger than the Ai by one half, and is of 
a uniform greyish-brown, which sometimes assumes a reddish tint. 
These two animals are natives of the hot parts of America, and, 
long ere this, would probably have been destroyed by the numerous 
Carnivora of that country, had they not possessed some means of de- 
fence in their nails.* 
Fossil skeletons of two animals of the order Edentata, of great size, have 
been discovered in America, one of which, the MecaruErium (a), Cuy. 
Oss. Foss. Tom. v. Part i, p. 174, has a head very similar to that of the 
sloths, but is deficient in the canines, and approaches, in the remainder 
* It is singular that the B. dydactylus was not known before the time of Seba, and 
that for a long time naturalists obstinately persisted in referring it, on the authority 
of that ignorant collector, to Ceylon. Erxleben has maintained its African origin, 
haying mistaken it for the Poto of Bosmann, which is a Galago. (See this last ge- 
nus). It is a fact that the Unau is only found in South America. 
Shaw, Gen. Zool., under the name of Brad. ursinus, has described an animal of 
which Iliger has made his genus Prochylus. M. Buchanan, Tray. in the Mysore, 
Vol. II. p. 198, has shewn it to be a true bear; and in fact we have satisfied our- 
selves, by inspecting the cranium of the very individual described by Shaw, that it 
os a bear of the species termed thick-lipped, which had lostits incisors. See Ursus, 
TC. 
(@= (a) The Megatherium is described as of the size of the Rhinoceros, uniting 
part of the structure of the Armadillo with that of the Sloth, and having claws of 
vast length. The Megalonix was an animal of the same description, hut somewhat 
smaller.—Ene. Ep. 
