59 



CHAPTER III. 



CONCLUDING REMARKS. 



In this short chapter I jjroiDOse to discuss ; first, the osteological 

 affiaities of the Catodontidoe, or family of sperm whales ; secondly, 

 the true characters which distinguish that family ; and thirdly, 

 the causes of their rarity. 



The first of these questions regards the animals to which the 

 sperm whale family, in the structure of their skeleton, come the 

 nearest. I have already, in a multitude of points, shown their 

 close afiinity to the dolphin family, and the following series of 

 Delpliinidce is arranged very nearly in the manner that Mr. Gray 

 has, in his late work on Geiacea, considered to be the natural 

 disposition of these animals. 



Normal Group, 



FLUVIATILE, 



DELPHINID.E. 



Symphysis of un- f a. Iniina, Gray. 

 der jaw more than | 

 half length of jaw, \ 



Aberrant Group. 



MARINE. 



f c. Hypeeooeoxtina, Gray. 



Symjihysis of un- 

 der jaw not half - 

 length of jaAV. d. Monoceratin'a, Gray. 



I e. Delphinina, Gray. 



\ Maxillary bones 

 I horizontal. 

 f Maxillary bones 

 I rising vertically on 

 -{ edge, so as to form 

 I a crest over the nos- 

 Urils. 



f Upper jaw tooth- 

 I less. Maxillary 



■' bones raised verti- 

 I cally on edge so as 

 I to form a crest over 

 Lthe nostrils. 

 f Upper jaw with 

 j few teeth. Maxil- 

 -J lary bones sub-hori- 

 I zontal, and rather 

 I plane. 



Upper jaw with 

 many teeth. Max- 

 illary bones sub-ho- 

 rizontal and plane. 



