SPECIES OF MAMMALS OF THE PACIFIC AREA 129 



Fig. 52 — Hump-hacked Whale 



of finback whales are smaller, from twenty-five to sixty-five feet 

 in length. 



Finbacks are slender of body, with a dorsal fin ; the head is 

 one-fourth or less of the total length, and the "muzzle" is broad 

 rather than deep. The throat and breast have numerous longi- 

 tudinal folds, and the whalebone is short and coarse. Finbacks 

 are found in almost all seas, but they are commoner in the cooler 

 waters than in the tropics. These whales are the species now 

 hunted commercially, most of the others being too rare to be 

 profitable. 



Toothed Whales, Dolphins, and Porpoises 

 Suborder Odontoceti 



Adult toothed whales always have teeth, but in some cases 

 these are not functional. The teeth are usually numerous and 

 peg-like, and the nostrils open by a single blowhole. The small 

 toothed whales with long, pointed "beaks" are usually called 

 dolphins; those without "beaks" or with small, rounded ones, 

 and with bulging "foreheads" are called porpoises. 



The Sperm Whale (Physeter) reaches a large size ; the males 

 are as long as eighty-five feet, but the females are much smaller. 

 The head occupies almost one-third of the total length. The 

 upper jaw and muzzle are barrel-shaped ; the lower jaw, bearing 

 the teeth, is slender and pointed. The spout is directed diago- 

 nally forward and is "slow." Sperm whales are often found in 



