SURVEY OF THE ORDERS OF MAMMALIA. 739 
‘“Cenoplacentalia,” which made, so to speak, a fresh start, with a 
premium on brains, and led to most of the modern types. In almost 
every case, it may be said that an order begins with small repre- 
sentatives, and that the giant forms almost always indicate the end 
of a race. 
SyvSTEMATIC SURVEY OF THE ORDERS OF MAMMALIA 
I. Sub-class PROTOTHERIA or ORNITHODELPHIA, Orders 
Monotremata, and (?) Allotheria or 
Multituberculata. 
II. 5 METATHERIA or DIDELPHIA, Orders Poly- 
protodontia and Diprotodontia. 
ITI. on EUTHERIA or MoONODELPHIA. 
Orders of EUTHERIA. 
1. Xenarthra. 
2. Nomarthra. 
3. Sirenia. 
4. Ungulata. 
Artiodactyla. ; 
Perissodactyla. } Ungulata tics 
Hyracoidea. 
Proboscidea. 
Extinct sub-orders. 
5. Cetacea. 
Mystacoceti—baleen cetaceans. 
Archzeoceti—(extinct types). 
Odontoceti—toothed cetaceans, 
6. Rodentia. 
Simplicidentata, 
Duplicidentata, 
4. Carnivora. 
8. Pinnipedia. 
g. Insectivora. 
10. Galeopithecide or Dermaptera. 
tx. Chiroptera. 
Megachiroptera. 
Microchiroptera. 
12, Prosimize or Lemuroidea. 
13. Anthropoidea. 
\ “ Edentates.” 
\ = Primates. 
