60 
MAMMALIA. 
tin more or less large upon the back, and longitudinal wrinkles on 
the lower part of the body. Fig. 18 represents a species of Rorqual, 
whose skin, perfectly preserved under a roof, and protected by 
railings, occupies a largo yard in the Jar din des Plantes at 
Paris. 
Whales properly so called have the head very large, about one- 
third of the entire length of the animal, and considerably arched, 
the back unprovided with a fin, and the lower parts of the body 
smooth or unwrinkled. 
Dr. Gray, of the British Museum, distinguishes four species of 
Right Whales — viz. the Northern Whale ( Balcena mysticetus) , the 
Fig. 18.— Rorqual {Physalus antiquorum ) . 
Western Australian Whale (R marginata ), the Cape Whale (B. 
Australis ), and the Japanese Whale (B. Japonica). He also divides 
the Rorqual series — which have a prominent and conspicuous fin 
upon the back, the plates, of baleen or whalebone short and broad, 
and the belly longitudinally plaited — -into Megaptera, with the 
flippers elongated and dorsal fin low ; Balcenoptera , with flippers 
of moderate length, the dorsal fin falcate, and situate two -thirds 
of the length of the animal backwards, vertebrae 46 or 48 ; and 
Physalus , with flippers of moderate size, the dorsal fin falcate, and 
situate further backwards, or at three-fourths of the entire length 
of the animal, the vertebrae numbering from 54 to 64. Even 
