6 4 6 



COLLEGE ZOOLOGY 



Gr. monos, one; trema, an opening). In certain respects the 

 skeleton agrees with that of the reptiles. 



The young before hatching live on the yolk contained in the 

 egg. After hatching, the young are for a time nourished by milk 

 from the mammary glands. These glands do not open at the 

 end of a papilla, or teat, but pour their secretions upon the hair 



of the abdomen. The 

 young either suck or 

 lick the milk from this 

 hair. 



There are three 



genera, each contain- 



ing 



Fig. 513. — The duckbill, OrnithorhyncHus 

 anatinus. (From Shipley and MacBride.) 



a single species. 

 The spiny ant-eater, 

 Ecliidna acideata, is 

 from fifteen to eighteen 

 inches in length. It 

 has a prolonged snout, 

 a mouth without teeth, 

 an extensile tongue, 

 and a covering of stiff 

 spines mixed, with 

 long, coarse hairs. It 

 lives in burrows and feeds upon ants. The egg is placed by the 

 lips of the mother within a fold of skin on the abdomen; here it 

 is protected until hatched. Proechidna, the long-snouted 

 echidna, is confined to New Guinea. 



The duckbill or platypus, Ornithorhynchus anatinus (Fig. 513), 

 is about as large as Echidna, but is adapted for life in the water. 

 It possesses webbed feet, a thick covering of waterproof fur like 

 that of a beaver, and a duck-like bill with which it probes in the 

 mud under water for worms and insects. The heels of the male 

 are provided with strong horny spurs connected with a duct from 

 a venom gland in the thigh. During the daytime the duckbiD 

 sleeps in a grass-lined, underground chamber at the end of a long 



