376 Proceedings of the 



the skull. In this specimen it measures nearly 5 inches. 

 The malar bone extends backwards as far as the articulating 

 surface of the lower jaw, of which it forms the outer edge. 

 In front, the malar becomes flattened from above down- 

 wards, until the upper and lower margins nearly join, thus 

 forming a broad, concave space for the eye to rest upon. This 

 peculiar form of zygoma bears an evident relation to the hori- 

 zontal flattening of the upper and under surface of the skull, 

 and greatly diminishes the resemblance which in many re- 

 spects exist between the rodent order of placental mammals 

 and the wombat. 



" A narrow ridge, two inches in length, directed from with- 

 in outwards, forwards and upwards, and slightly concave trans- 

 versely, forms the articular surface for the lower jaw. This 

 remarkable structure of the glenoid cavity permits of free 

 movement in every direction, and in this peculiarity of mechan- 

 ism it differs from the kangaroo and koalo amongst its con- 

 geners, and from the rodent order of placental quadrupeds. 

 The palate bones are connected by a bridge in the line of the 

 longitudinal palatine suture, and to the maxillaries by the 

 transverse suture. This bridge, formed by the under surface 

 of the crest of the palate bone, divides the two posterior pala- 

 tine foramina, which, in the form of two elongated fissures, 

 extend from the elevated posterior curved edge of the palate 

 bones, giving origin to the muscle of the uvula, nearly to the 

 maxillaries. 



" Two smaller foramina are seen behind these in the under 

 and back part of the nasal plate of the palate bone. The an- 

 terior palatine fissures or foramina incisiva, less in size, but 

 similar in shape, are not entirely confined to the premaxillary 

 bones, the anterior extremities of the palatine process of the 

 maxillaries entering slightly into their formation. The su- 

 tural connections of the premaxillaries are well marked in this 

 skull. They articulate largely with the nasal bones, but do 

 not entirely separate the maxillaries from the nasal. There 

 is a distinct, but very narrow process of the maxillary bones 

 running between the malar and premaxillary, until it spreads 

 out into a small, irregular quadrilateral-shaped bone in front 

 of the lachrymal, like one of the so-called ossa wormiana. 



