CHORDATA 





tinct anal and urogenital openings; and, further, they are the 

 only mammals which are oviparous. 



There are only two families; the first is represented 1 

 single animal, Ornithorhynchus paradoxus or anatimis, known 

 popularly as the platypus, duckbill, or duckmole ( Fig. 354). |- 

 jaws resemble a duck's bill, and there are no teeth in the adult, 

 although they are found in the embryo. The duckbill glows to 

 be about forty-five centimeters in length from the tip of the bill 

 to the tip of the tail ; it is a dark brown in color and covered 

 with woolly hairs, and longer, stiff contour hairs. The feel are 

 webbed and the toes are provided with claws, as the animal is 



Fir.. 354. Ornithorhync litis anatinus, the duckbill. (After Vogt and Sprecht, from Parker 



and Haswell's Manual.) 



largely aquatic and uses its feet for swimming and also for 

 burrowing. In the male each hind foot bears a sharp, pro- 

 jecting spur. The eyes are small and there are no projecting 

 ears. They feed on worms and various small aquatic animals 

 and have cheek pouches in which the food may be temporarily 

 stored. They burrow a chamber in the ground near the water, 

 line it with leaves, and thus fashion a nest in which the eggs are 

 deposited and the young cared for. 



The second family is not strikingly like the first in general 

 appearance; it is represented by the spiny ant-eaters, of which 

 there are several species (Fig. 355). One species, Echidna 

 hystrix, is about thirty centimeters long; others are somewhat 

 larger. The beak is much shorter and narrower than in Or- 

 nithorhynchus, the tail is very rudimentary, the feet are not 



