58 



from sucli a mass of confusion so much correct information 

 resjDGcting an animal which he only knew by Sir Eobert Sibbald's 

 figure. The truth is, that the Eiiphysefes comes much closer in 

 external appearance to the black fish than to the sperm whale. 

 It in a manner proves the existence, now or formerly, of such a 

 species as Sibbald and Fabricius described from the northern part 

 of the Grerman Ocean. Like the Euphysetes, the black fish is 

 said to have a round head with a depressed and truncated snout; 

 it had also a dorsal fin, and its blowhole was situated on the 

 middle of the head. Now, as the skeleton of the Eupliysetes 

 comes so near to that of Gatodon, it is impossible that Mr. Gray 

 can be wrong in considering the black fish (the Fhyseter Tursio 

 of Linnajus) to belong truly to the family of sperm whales. 



The known genera that belong to the family of Gatodontidcd 

 may, by their external appearance, be shortly characterised as 

 follows, viz.: — 



No dorsal fin, but only 

 a hump instead. Blow- 

 hole at the extremity of 

 snout. 



1. Catodon. 



2. KOGIA? 



Head between a third 

 and fourth of the whole 

 length. 



C Head 

 X angular, 

 [ front ? 



modei-ate, tri- 

 and pointed in 



f3. EUPHYSETES. 



Dorsal fin. BloAvhole -! 

 on middle of head, j 



L4. Physetee. 



Head moderate, like 

 that of a dolphin, and 

 truncated in front. 



Head half length of 

 rest of skeleton ? Blow- 

 hole covered by an oper- 

 culum or flap ? 



But of anatomical characters by which we may separate the 

 JEuphysetes from all other described genera of the sperm whale 

 family, there is none so striking as that ridge of bone which 

 divides the back part of the spermacetic cavity into two lesser 

 cavities nearly equal in size. 



