380 THE LIVING ANIMALS OF THE WORLD 



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WOOLLY 



AMERICAN OPOSSUM 



MONOTREMES, OR EGG-LAYING 

 MAMMALS 



WITH this group or order of the Mam- 



malian Class we arrive, as it were, on the 



borderland between the mere typical Mammals 

 and Reptiles. In the last group, that 

 of the Marsupials, it was observed that the 

 young were brought into the world at an 

 abnormally early and helpless phase of their 

 existence, and usually consigned, until able 

 to see and walk, to a variously modified pro- 

 tective pouch. With the Monotremes a yet 

 lower rung in the evolutional ladder is reached, 

 and we find that the young are brought into 

 the outer world as eggs, these being in the one 

 case deposited in a nest or burrow, and in the 

 other carried about by the parent in a rudi- 

 mentary sort of pouch until they arc hatched. 

 The living representatives of this singular 

 mammalian order are but few in number, being 

 restricted, in point of fact, to only two distinctly 

 differentiated family types the Echidna or 

 Porcupine Ant-eater, and the Platypus. These 

 monotremes, moreover, like the majority of 

 the existing marsupials, are limited in their 

 distribution to the Australasian region. The 

 single species of the Platypus is only found 

 in Tasmania and the southern and eastern 

 districts of the Australian Continent, while the Echidna numbers some three recognised species, 

 two of which belong to Australia and Tasmania and the third to New Guinea. 



THE ECHIDNA 



The ECHIDNA, PORCUPINE ANT-EATER, or " PORCUPINE," as it is commonly called by the 

 Australian colonists, would seem at first sight tojrepresent an animal in which the characters 

 of the hedgehog and the common porcupine are interblcndcd, the innumerable spines being 

 longer than those of the former, but less in length than those of the last-named animal. The 

 head, with no externally visible ears and remarkable elongated beak-like snout, however, at 

 once proclaims it to be altogether distinct from these. The animal has no teeth, and the 

 tiny mouth at the termination of the beak-like snout simply constitutes an aperture for the 

 extrusion of the worm-like glutinous tongue, wherewith, after the manner of the true ant-eaters, 

 it licks up the inhabitants of the ants' nests upon which it feeds. For tearing down the 

 ants' nests and obtaining its customary food, as also for its inveterate burrowing propensity, 

 the feet, and more especially the front ones, are provided with strong, blunt, and very powerful 

 claws. The male animal is in addition armed on the hind feet with a peculiar supplementary 

 spur, which is, however, still more conspicuously developed in the platypus. 



Three distinct species of the echidna are recognized by zoologists. The one peculiar to 

 the cooler climate of Tasmania is remarkable for its more slender spines, the much greater 

 abundance of the long bristle-like hairs, and the thickness of the seal-brown under-fur, as 

 compared with the typical Australian form. In North-west New Guinea the largest and most 

 aberrant form is met with. Normally it has only three toes in place of five to each foot, 

 the spines are very long and thick, the body is deeper and more compressed, and the animal 

 stands comparatively high upon its feet. 



This animal is about the size of a large mouse. It carries its young 

 on its back, their tails being entivined round that of their parent 



