18 BULLETIN NO. VII. 



The caracoids are absent or are represented by small processes 

 of the scapula. There are no marsupial bones. The ear has a 

 complicated spiral cochlea. The young are brought forth in 

 an advanced stage of development, not requiring to be forcibly 

 fed by the mother. The corpus callosum is large and the 

 angle of the mandible is not inflexed. 



The sub-class Monotremata includes the orders Carnivora, 

 Rodentia, Insectivora, Edentata, Chiroptera, Primates, Pinnipedia, 

 Cetacea, Sirenia, Proboscidea and Ungulata, or in other words, 

 all the cats, dogs, bears and weasels, all the squirrels and 

 rabbits, shrews and moles, sloths and ant-eaters, bats and 

 flying foxes, seals and walrusses, whales and dolphins, sea-cows 

 and dugongs, elephants and tapirs, and all the kine and horses 

 as well as all races of mankind. 



As being most highly specialized and departing most from 

 what is assumed as the primitive type of mammalia, this sub 

 class is considered the highest of the three. Fossils indicate 

 that the lower sub-classes were once proportionally more num- 

 merous, especially the marsupials. 



