286 



CHAPTER XXXIX. 



ORDERS OF MAMMALIA. 

 MOXOTEEMATA AND MaESUPIALIA. 



Order I. Moxotee^la.ta. — The first and lowest order of the 

 Mammalia is that of the Moiwtrcmata, containing only two 

 genera, both belonging to Australia — namely, the Duck-moles 

 {OrnitliorJiynchv.s) and the Porcupine Ant-eaters {Echidna). 



The order is distinguished by the following characters : 

 The intestiiu opens into a " cloaca" which receives also the 

 products of tJie urinary and generative organs, which discharge 

 themselves into a urogenital canal — the condition of parts 

 being very much the same as in Birds. The Jaws are either 

 wholly destitute of teeth (Echidna) or are furnished with four 

 horny 'plates whicli act as teeth (Ornithorhynchus). The 'pectoral 

 arch has some highly hird-like characters, the most important of 

 these being the e^ctension of the coracoid hones to the anterior end 

 of the sternum. An interclavicle is also j^'^^ent. The females 

 'possess no Tnarsupial pouch, hit the pelvis is furnished vnth the 

 so-called " marsupial hones" heing special ossifications of the in- 

 ternal tendons of the external oblique imcscles of the abdomen. 

 The mammary glands have no nipples, arid their ducts open 

 either into a kind of integumentary pouch (Echidna) or simply 

 on a flat surface (Ornithorhynchus). The young are destitute 

 of a placenta., err, in other words, 'no vascidar con'nectio'n is 

 established between the fcetus and the mother. The feet have 

 five toes each, armed with claws, and the males carry per- 

 forated spurs on the back of the tarsus (attached to a supple- 

 mentary tarsal bone). 



