332 PROF. OWEN ON THE CLASSIFICATION 
Mammalia. In the ordinary Fere, for example, in the Quadrumana and in the Rodentia, 
as likewise in the Pachyderma and Ruminantia, the number of grinders developed on 
each side of each jaw, which are not subject to vertical displacement and succession, is 
never more than three, while in the corresponding groups of Marsupials it is always 
four’. 
These coincidences in the Marsupialia, of more or less important peculiarities of struc- 
ture, which cannot be connected with their reproductive ceconomy, are truly remarkable, 
and their detection and generalization give peculiar interest to anatomical investigations 
of the Marsupial animals. 
The following is a tabular view of the subordinate groups of the Marsupialia regarded 
as a distinct Order of Implacental Mammalia. 
CLASSIFICATION OF THE MARSUPIALIA. 
Tribes. Families. Genera. Subgenera. 
SarcoPHaGa. 
Three kinds of teeth ; canmes asics 
long in both jaws; a sim- Daspurive Teens 
ple stomach; no intestinum SEs SN ACO Phar 1 
ascogale. 
cecum. 
Extinct transitional forms .. ............... Tua =e , : \ Fossil. 
ENTOMOPHAGA. 
Three kinds of teeth in both 
jaws; a simple stomach; a : ; 
moderately long éatestinum Ambulatoria....... Myrmecobius. 
cecum. 
a Cheropus. 
DLILALOTIGast = thet ened nes 
. : Didelphys. 
STENTS 6 Abn OGe Didelphyssy- cs temenstenaicte { Giese ee 
CarPoPrHAGa. 
Anterior incisors large and Cuscus. 
long in both jaws; canines Phalangista......... ‘ Fseudocheirus. 
inconstant; stomach sim- pp qangicti Ds Tapoa. 
ple, or with a special gland ; DEE es Sees Petaurista. 
a very long intestinum ce- Petamtnsacscs sered lise ‘ Belidia. 
cum. Acrobata. 
Phascolarctide ..... Phascolarctus. 
PorrHaGa. 
Anterior incisors large and c Hypsiprymnus. 
long in both jaws; canines BIB a { Macropus, 
present in the upper jaw 
only, or wanting. A com- 
plex stomach ; a long intes- 
tinum cecum. | 
RuIzopHaGa. 
Two scalpriform incisors in 
both jaws; no canines. Sto- é 
mach with a special gland; Phascolomyide..... { eee Se Fossil 
Fis chinks: wale al iprotodon......... ossil. 
vermiform appendage. 
1 I need hardly remind the zoological reader, that the teeth which are displaced by a second set succeeding 
them in the vertical direction, are, in Man, the incisors, canines, and false molars, the successors of which are 
