410 DR KNOX on the Dentition of the Dugong, and onihe 



The length of each pectoral extremity is 17 inches ; these 

 are imperfect, however, inasmuch as few of the ringers are pre- 

 sent. The bones of the pelvis are entirely wanting ; that is, I 

 presume, they have been lost in the original preparation of the 

 animal. 



Feet. Inches. 



Length of head, , . . . . . . . 2 



Breadth, 17 



The tusks are carried in the maxillary bone. The summit 

 at the top of the head is removed to the left side to the distance 

 of about an inch from the mesial plane, so that, looking at the 

 head from behind, it has a singular unsymmetrical appearance, the 

 right side of the occipital bone appearing so much broader than 

 the left side ; whilst looking at the face on the upper surface, the 

 left side again preponderates over the right, in consequence of 

 the much greater size of the left maxillary bone, as it requires to 

 carry the fully developed tooth. This difference in breadth and 

 depth does not extend to the inter-maxillary bones, or very 

 slightly ; and indeed, superiorly, the inter-maxillary bone of the 

 right side is the larger of the two ; so that the want of symmetry 

 follows a different law in the cranium and upper part of the face 

 from what it does in the lower part of the face. The distance 

 between the orbit of the right side and the anterior margin of 

 the blow-hole of the same side, being nearly an inch greater than 

 on the left. The law, therefore, seems to be, that the greater 

 development with regard to the cranium is on the right side, and 

 with regard to the face, on the left side, and the head has alto- 

 gether a twisted appearance. This singular want of symmetry 

 in the bones of the cranium and face has not been remarked by 

 M. CUVIEBJ though in the engraving of the cranium of the nar- 

 wal the appearance I speak of has been very accurately repre- 

 sented by the engraver. The capacity of the cranium is large, 



