CHORD. VIA 





the hind feet webbed. The remaining marsupials are confined 

 to the region of Australia, and include such l\ pes as the wom- 

 bats, little burrowing animals about sixty centimeters long, with 

 large head, short neck and legs, and rudimentary tail; the 

 koala or native bear of New South Wales, arboreal in habit ; 

 the phalangers, little arboreal animals, ranging from eight or 

 ten centimeters in length to the size of a cat, having long, pre- 

 hensile tails ; the burrowing bandicoots, about as large as a 

 small rabbit; the kangaroos and their allies (Fig. 357), which 

 are the largest and the most numerous of the Marsupialia and 

 have the hind legs and tail very well developed, — the giant 

 kangaroo, Macropus major, can make leaps of five or six meters 

 when pursued; the Tasmanian devil, a carnivorous genus about 

 the size of a badger; and the zebra wolf or pouched dog, about 

 the size of a wolf, carnivorous and nocturnal in habit. 



SUBCLASS III. MONODELPHIA, OR PLACENTALIA 



The Monodelphia (Gr. /j.6l>o<;, single, and 8e\(f)vi, womb), or 

 Placentalia (Lat. 

 placenta, a cake), 

 are sometimes 

 called the Eutheria 

 (Gr. ev, well, and 

 Bvplov, beast), — 

 the Metatheria 

 and Eutheria be- 

 then collec- 

 tively known as 

 Theria, while some 

 zoologists apply 

 the name Eutheria 

 to both groups. 

 They may be dis- 

 tinguished by the 

 fact that the vagina 

 is always single; 

 the uterus may be 



FIG. 358. Mm decumanus, the common rat; eml 

 which the embryonic membranes have been 1 emoved ; n 

 size, 13 mil : long, ^.embryo disp] iced I 



position in the concavity of the placenta; /\ placenta, which is 

 shaped like a meniscus; um, umbilical cord, which contains 

 single CM' it may be the blood vessels passing between the embryo and ll 



. ///, wall of the uterus, cut open and k. I Drawn 



more or less eom- 



a preserved specimen, by the author.) 



