CETACEA. 



197 



posed between the antorbital processes of the frontal and 

 maxilla and the malar. 



The palate is long and narrow, with a strong keel or 

 ridge in the middle line. The surface on each side, sloping 

 upwards and outwards, is perforated by many large foramina 

 to permit the passage of blood-vessels and nerves to the 

 matrix of the baleen, or " whalebone," which covers it in 

 the Hving animal. It is chiefly formed by the maxilla, 

 behind which are large palatines and very small and widely 

 separated pterygoids. 



TxO 

 Per 



Fig. 63. — Section of the skull of a foetal Southern Right Whale {Balcena australis), y', . 

 PMx premaxilla ; Na nasal ; Fr frontal ; Pa parietal ; SO supraoccipital ; OS 

 orbitosphenoid ; AS alisphenoid ; ExO exoccipital ; Per periotic ; BO basi- 

 occipital ; Ty tympanic ; BS basisphenoid ; Sq glenoid articular surface of squa- 

 mosal ; Pt pterygoid ; PI paiaiine ; PS presphenoid ; Vo vomer ; Mx maxilla ; 

 cp coronoid process of mandible ; cd condyle ; dg dental groove ; ing remains of 

 groove which lodged Meckel's cartilage. No part of the mesethmoid is ossified. 



The zygomatic process of the squamosal is an immense 

 trihedral pillar in Balcena, having the large shallow glenoid 

 fossa on its under surface removed considerably from the 

 middle of the cranium, so as to give sufficient width to the 



