﻿2So Allen's naturalist's library. 



ORDER MULTITUBERCULATA. 



As already mentioned, the serial position of that re- 

 markable group of extinct Secondary Mammals, generally 

 known by the name of Multituberculata, cannot at present be 

 definitely determined, although the balance of evidence is in 

 favour of their being more or less intimately related to the 

 existing Monotremes. Whether, however, they should be 

 included in the same order with the latter, or whether, as is 

 more probable, they should constitute an order by themselves, 

 is likewise a matter of uncertainty. If they really indicate a 

 distinct order, it may prove that the Monotremata and Multi- 

 tuberculata constitute two ordinal groups in the sub-class 

 Prototheria. 



From a superficial resemblance between the teeth of certain 

 members of the family and those of the Rat-Kangaroos, it was 

 at one time considered that the Multituberculata belonged to 

 the Diprotodont Marsupials, but subsequent investigations have 

 led to the abandonment of this view. 



The main reasons for placing this group in the neighbour- 

 hood of the Monotremes are, firstly, that while their moLir 

 teeth are quite unlike those of all other Mammals, they presents 

 certain distant resemblance to the deciduous teeth of the Duck- 

 bill ; and, secondly, that in the one instance where the bones 

 of the shoulder-girdle have been discovered, these are of the 

 characteristic Monotrematous type ; that is to say there is 

 a distinct coracoid and metacoroid, and probably, therefore, 

 an iiiterclavicle. 



Ranging throughout the whole of the Secondary period, that 

 is to say from the Triassic to the Cretaceous rocks inclusive, 

 the Multituberculata also survived into tlie lowest division of 



