THE DUCK-BILL ■, OR MULLINGONG. 
63T 
slightly variegated by differently tinted hairs, and the head and face being darker than the body 
and limbs. The hair has a cnrions, hay -like aspect, being coarse, flat, and harsh towards the 
extremity, although it is very fine towards the root. Owing to the color and structure of the 
hair, the Ai can hardly be distinguished from the bough under which it hangs, and owes much 
of its safety to this happy resemblance ; for its flesh is very good, and, in consequence, the 
poor creature is dreadfully persecuted by the natives, as well as by the white hunters. The 
cry of this creature is low and plaintive, and is thought to resemble the sound Ai. The head 
is short and round, the eyes deeply sunk in the head, and nose large and very moist. 
The young of the Ai, as well as those of the other Sloths, cling to their mother as soon as 
they are born, and are carried about by her until they are able to transfer their weight from 
their parent to the branches. Several other species of Sloths are known to exist, but all are 
similar in appearance and habits. 
The family Brady podidce embraces the present living Sloths. They are especially confined 
to the forests of Brazil, Bolivia, and Guatemala. Two species are known of the genus Cho- 
Icepus — the Two-toed and Hoffman’s Sloths. 
The genus Bradypus includes one species — the Ai, or Three-toed Sloth. A good figure is 
seen herein. Several small Sloths, embraced in the genus Arctopithecus , are indigenous in 
South America. 
THE MONOTREMES. 
There are few animals which have attracted such universal attention, both from scientific 
men and the reading world in general, as the Mullixgoxg, Duck-bill, or Platypus, of 
Australia. This little creature, the largest being but twenty-two inches in length, has excited 
more interest than animals of a thousand times its dimensions, on account of its extraordinary 
shape and singular habits. It is most appropriately called the Duck-bill, on account of the 
curious development of the intermaxillary bones, which are very much flattened and elon- 
gated, and their ends turned inwards in a kind of angular hook. The lower jaw is also 
lengthened and flattened, although not to such an extent as the upper, and the bones are 
covered with a naked skin. 
In the stuffed and dried specimens the “beak” appears as if it were composed of the 
black leather taken from an old shoe, but in the living animal it presents a very different 
aspect, being soft, rounded, and of a pinky hue at its tip, mottled with a number of little 
spots. Dr. Bennett, to whom the zoological world is so much indebted for his researches into 
the habits of this curious animal, kindly showed me some excellent drawings, which gave a 
very different idea of the animal from that which is obtained by the examination of stuffed 
skins. The beak is well supplied with nerves, and appears to be a sensitive organ of touch, 
by means of which the animal is enabled to feel as well as to smell the insects and other 
creatures on which it feeds. 
The Mullingong is an essentially aquatic and burrowing animal, and is formed expressly 
for its residence in the water, or under the earth. The fur is thick, soft, and is readily dried 
while the animal enjoys good health, although it becomes wet and draggled when the creature 
is weakly. The opening of the ears is small and can be closed at will, and the feet are fur- 
nished with large and complete webs, extending beyond the claws in the fore-limbs, and to 
their base in the hind-legs. The fore-feet are employed for digging as well as for swimming, 
and are therefore armed with powerful claws rather more than half an inch in length, and 
rounded at their extremities. With such force can these natural tools be used, that the Duck- 
bill has been seen to make a burrow two feet in length through hard gravelly soil in a space of 
ten minutes. While digging, the animal employs its beak as well as its feet, and the webbed 
membrane contracts between the joints so as not to be seen. The hind-feet of the. male are 
furnished with a spur, about an inch in length, curved, perforated, and connected with a gland 
situated near the ankle. It was once supposed that this spur conveyed a poisonous liquid 
