1 84 A SO OK OP WHALES 



as far as they ought to be separated from the 

 Ziphioids. This sub-family will contain two genera, 

 viz., Physeter and Kogia. These two genera agree 

 to differ from what may be termed the Ziphiinae by 

 two characters of some little importance ; these are 

 the presence of numerous teeth in the lower jaw, and 

 the existence of only a lacrymal bone ; there is at any 

 rate only one bone, which may of course conceivably 

 represent a fused lacrymal and malar. There are two 

 in Ziphiids. To these two characters, which Sir 

 William Flower uses to ally the " Sperm whales 

 giant and pygmy," we may add the single lateral (left) 

 blow hole. Sir R. Owen at least figures a single 

 blow hole* in Kogia simus, which is longitudinal as 

 in Physeter, but not S-shaped as in that creature. 

 Of the two genera of Physeterines, Kogia is in many 

 ways the least specialised form. It has the blow hole 

 in what is (for a whale) a more normal position. We 

 cannot, it seems reasonable to suppose, regard the 

 terminal blow hole of the Cachalot as primitive 

 because it is so far away from the shrunken nasal 

 bones ; it must be at most a return to a primitive 

 state of affairs. The falcate dorsal fin of Kogia may 

 be considered in the same light, and also generally 

 the more delphinoid form of the head and body ; the 

 form of the Cachalot with its disproportionate head 

 is surely a secondary acquisition. In the skull too 

 there are features which seem to point to the same 

 conclusion. The elongated rostrum of the Cachalot 

 contrasts with the short snout of the Pygmy Sperm 



* A rudimentary second one exists in Kogia pottsi. 



