350 CETACEA. 



to considerable depths, where the pressure ot water is enormous, they 

 are provided with a covering of great elasticity. Their skin is thick- 

 ened, and made up of a texture of interwoven fibres enclosing an im- 

 mense quantity of oil or blubber, which is admirably adapted to resist 

 compression. This thick integument of fat retains the animal heat, and 

 thus enables the Cetaceans to inhabit the coldest regions of the ocean, 

 and as oil is lighter than water, it contributes greatly to the buoyancy 

 of these unwieldy animals. A dead whale floats, but the carcass, when 

 stripped of blubber, sinks immediately. 



The order Cetacea is divided into two sub-orders ; Mystaceti, or 

 true whales, which have the mouth provided with baleen or whalebone, 

 and Odontoceti, sperm-whales, blackfish, porpoises, and the like, which 

 have teeth in one or both jaws. The first sub-order contains tzvo families, 

 the second, /^?^r. 



THE RIGHT WHALES. 



The family Bal^NID.-e is divided into six genera and fourteen species, 

 but most of the latter are imperfectly known, and their classification is 

 by no means settled ; it comprises the " right " whales, of which the 

 Greenland whale is the most important. 



GENUS BAL^^NA. 



Into this genus three species are admitted without controversy ; but a 

 fourth, the so-called "Scrag Whale of Dudley," has been the subject of 

 great doubt, as it is not known to whalers now-a-days, and is supposed 

 by Cuvier to be a mutilated Rorqual. 



The Greenland or Right Whale, Baleena Mystaeetus (Plate 

 XXVII), inhabits the Northern seas, and when full-grown, attains a 

 length of sixty to seventy feet, with about thirty to forty feet in girth. 

 Its color is velvety black upon the upper part of the body, gray at the 

 junction of the tail and at the base of the fins, and white on the abdomen. 

 The head is remarkably large, being about one-third of the length of the 

 entire bulk. The jaws open very far back, and average sixteen feet in 

 length, seven feet wide, and ten or twelve feet in height, affording space 

 for a jolly-boat and her crew to float in. The tail is enormousl}' power- 

 ful, enabling the largest whales, measuring eighty feet in length, to leap 



