420 



PHYSETERIDiE. 



there is a protuberance not far from the tail, and some- 

 times one or two smaller ones. The flippers are small 

 and slightly grooved longitudinally ; the tail is very broad 

 and divided into two equal lobes. The upper parts are 

 very dark, almost black, the sides lighter, and the belly 

 silvery grey. 



The usual length of the adult males appears to be about 

 sixty feet, the largest authentic measurement given by 

 Bennett being seventy-six feet in length by thirty-eight 

 in girth. Females are stated by Beale to be very much 

 smaller than the males, and Prof. Flower remarks that 

 very small but apparently adult jaws are preserved in 

 museums, which are either those of females or indicate a 

 distinct and smaller species. 



The skeleton has forty-nine or fifty vertebrae and ten 

 pairs of ribs. The best description of the osteology of the 

 Sperm -Whale is contained in the paper by Mr. Flower to 

 which we have so often referred. 



