OKNITHODELPHIA. 437 



of the oviducts opening into two separate vaginae, which have 

 distinct apertures in the urogenital canal, the rectum being 

 separated. Chorion absent. Coracoids reduced, not reaching 

 the sternum. Males without cloaca. To this group belong the 

 Marsupialia or Pouch-Bearers. 



C. The Monodelphia, which have the two uterine enlarge-: 

 ments of the oviducts united to form one uterine cavity, with 

 its two cornua, and by the single vagina, which is completely 

 separate from the rectum. Chorion and placenta present. 

 Coracoids reduced to a process only. This division contains all 

 the remaining mammals, which include the following orders : — 

 (i) Edentata or Sloths. 



(ii) Sirenia or Manatees. 



(iii) Cetacea or Whales. 



(iv) Uiigulata or Hoofed Animals. 



(v) Hyracoidea or Conies. 1 tt i t 



(vi) Proboscidea or Elephants. J 



(vii) Garnivora or Beasts of Prey, 

 (viii) Rodentia or Eodents. 



(ix) Ghiroptera or Bats. 



(x) Insectivm-a or Moles, Shrews, &c. 



(xi) Quadrumana or Monkeys. 



(xii) Bimana or Man. 

 Seven of these orders only are met with in the British Isles. 

 The other five need little consideration. 



A. ORNITHODELPHIA 

 = PROTOTSERIA. 



Order— MONOTREMATA. 



These are the lowest animals, and approach the Sauropsida 

 nearer than other Mammalia. The two most noted forms are 

 the Duck-Bill (Omithorhynchus paradoxus) and the porcupine- 

 like Echidnas. These animals all have a regular cloaca ; there 



}^ 



Primates. 



