4 
RoOvENTIA. 
In this order, so far as yet observed, the supraglenoid and postparictal 
foramina are never present, while the mastoid is rarely, and the sub- 
squamosal ig generally, represented. The ridge connecting the zygoma 
with the inion being weak, the difference between this foramen and the 
postsquamosal is less marked in this order than in the Marsupialia. It is, 
however, always on the inferior border of the squamosal bone. 
Lepus and Lagomys ; no foramina. 
Lagidium ; no foramina. 
Cercolabes ; no foramina. 
Lagostomus, Geomys and Erithizon ; an enormous postglenoid w ithout 
internal canal. 
Capromys, Calogenys, Seiurus, Haplodontia, Hesnoncmys, Mus ; post- 
glenoid and postsquamosal only. 
Hystriz, Hydrocherus, Neotomu and Arvicola ; postglenoid and post- 
squamosal foramina confluent ; no others. 
Castor, Cynomys and Spermophilus ; postglenoid, postsquemosal and 
mastoid. : 
INSECTIVORA. 
The foramina are very much as in the Rodentia in the smaller forms, 
and as in the Carnivora in the larger. 
Blarina, Condylura and Scalops ; postsquamosal only. 
Erinaceus ; postglenoid and postsquamosal only. Mystomys the same, 
according to Allman’s figures. 
Centetes ; postglenoid, postparietal and mastoid. 
Solenodon (from Peters’ figures) ; postglenoid and postparietal. 
CHIROPTERA. 
In some members of this order the foramina are, as in many Carnivora, 
limited to the postglenoid and postparietal. 
Scotophilus (fuscus),; postglenoid, postparicta]l and mastoid. 
Pteropus ; postglenoid, subsquamosal and postsquamosal. 
CARNIVORA. 
In this order the foramina are few in number, and are very well defined. 
None of them possess more than three, while the specialized forms, both 
terrestrial and aquatic, do not possess them. 
Trichecus and Arctocephalus ; no foramina. 
Phoca ; a rudimental postglenoid. 
Ursus, Arctotherium and Hyenodon, postglenoid, mastoid and post- 
parietal. 
