124 MONOTREMATA 
which are caught under water, the sand and small stones at the 
bottom being turned over with the bill. The creatures appear 
at first to deposit what they have thus collected in their cheek 
pouches, and when these are filled they rise to the surface and 
quietly triturate their meal with the horny plates before swal- 
lowing it. Swimming is effected chiefly by the action of the 
broad forepaws, the hind feet and tail taking little share in 
locomotion in the water. When asleep they roll themselves into 
a ball, as shown in the figure. In their native haunts they are 
extremely timid and wary, and very difficult to approach, being 
rarely seen out of their burrows in the daytime. Mr. 
Crowther, who has supplemented the often quoted observations 
of Dr. Bennett upon the habits of these animals in confinement, 
says, ‘They soon become very tame in captivity ; in a few days 
the young ones appeared to recognise a call, swimming rapidly 
to the hand paddling the water; and it is curious to see their 
attempts to procure a worm enclosed in the hand, which they 
greedily take when offered to them. I have noticed that they 
appear to be able to smell whether or not a worm is contained in 
the closed hand to which they swim ; for they desisted from their 
efforts if an empty fist was offered.” When irritated they utter a 
soft low growl, resembling that of a puppy. 
Family ECHIDNIDZ. 
Cerebral hemispheres larger and well convoluted. Facial portion 
of skull produced into a long, tapering, tubular rostrum, at the 
end of which the anterior nares are situated. Rami of mandible 
slender, styliform. Opening of mouth small, and placed below the 
extremity of the rostrum. No teeth or laterally placed horny plates, 
though the palate and tongue are furnished with spines. Tongue 
very long, vermiform, slender, and protractile. Lining membrane 
of small intestine villous, but without transverse folds. Feet not 
webbed, but with long strong claws fitted for scratching and 
burrowing. The hinder feet with the ends of the toes turned 
outwards and backwards in the ordinary position of the animal 
when on the ground. Tail very short. Acetabulum with a large 
perforation, as in Birds. Calcaneal spur and gland of the male 
much smaller than in Ornithorhynchus. Fur intermixed with strong, 
sharp-pointed spines. Terrestrial and fossorial in habits, feeding 
exclusively on ants, and recalling in the structure of the mouth and 
various other parts relating to their peculiar mode of life the true 
Anteaters of the order Edentata. 
The Echidnas or Spiny Anteaters constitute a family which 
appears in some respects to be less specialised than the Ornitho- 
rhynchide. According to Mr. O. Thomas, all the living forms may 
