74 



WHALES AND DOLPHINS 



lower jaw, at any rate in a specimen stranded at Ferndale, 

 California, projecting beyond the tip of the upper. So far as is 

 known there is little difference in colour between the species : 

 both are black dorsally and light coloured or white below. A 

 specimen of B. arnuxii, caught outside Deception Island, South 

 Shetlands, is described as having " upper parts bluish-black, 

 under parts greyish to white with tiny black flecks, to dark 

 grey. A large number of white scars covered the body. The 

 two large teeth are anterior to the front of the upper jaw ". 



Fig. 72. — Lower jaw of Bcrardius. 



B. bairdii is distinguished from B. arnuxii by. its greater 

 size ; it reaches a length of about 42 feet — a giant among 

 Ziphioid whales— whereas the other is full grown at 32 feet. 

 Available knowledge of the two species indicates that their 

 distribution does not overlap. 



In Berardius the skull is much more nearly symmetrical 

 about the middle line than in any other Ziphioid. The tubercles 

 are present near the proximal end of the rostral portion of the 

 skull, as in Hyperoodon, but are not nearly so greatly developed 

 as in that species. In B. arnuxii the skull is one-seventh of 

 the body length, in B. bairdii it is one-eighth, so that although 

 the latter is the larger species, the head is relatively smaller. 

 Besides the characters mentioned, many osteological differences 

 distinguish the two Berardius species from one another and 

 from the remaining Beaked Whales, but such internal distinc- 

 tions are outside the scope of this work. Exceedingly little is 

 known about the habits of this genus ; the total number of 

 known specimens is in itself quite small. 



