APPENDIX. 



327 



formula, and by certain osteological characters, of which 

 the following are the principal. 



The alveolar series of the two sides of the upper jaw, 

 in the younger skull of Halicore australis (fig, 1), have a 

 greater anterior convergence, and the outer boundary or 

 curve of the series is more convex than in Halicore indicus 

 (fig. 2). The basi-occipital bone, and parietal bone, are 

 broader in proportion to their length in Halicore australis. 

 The part of the deflected maxillary and intermaxillary 

 bones, which is bounded posteriorly by a ridge, is longer 

 in proportion to the breadth of the same part in Halicore 

 australis (fig. 3), than in Halicore indicus (fig. 4). 



Fig. 3.— Skull of Australian Dugong. 



Fig. 4. — Skull of Indian Dugong, 



