CETACEA. 183 



united; the teeth implanted in the incisive bone are permanent, and grow 

 to such a size as to become true pointed tusks, but of whicli the greater 

 portion remain covered by thick fleshy lips, bristled, and with mustachios. 

 The body is elongated, and the tail terminated by a crescent-shaped fin. 

 One species only is known, the 



Hal. dugong; Siren; Sea-Cotv, &c. ; Renard, Poiss. des Indes, 

 pi. xxxiv, "f. 180; Home, Phil. Trans, and F. Cuv. Mammif. (The 

 Dugong). It inhabits the Indian Ocean, and is frequently con- 

 founded by travellers with the Manatus. 



Stellerus, Cuv — Rytina,* lllig. 



The Stelleri appear to have but a single compound grinder on each 

 side, with a flat crown, and bristled with plates of enamel. Their fins 

 have not even the little nails observed on those of the INIanatus. Accord- 

 ing to Steller, the first, and hitherto the only one- who has described them, 

 tlieir stomach also is much more simple. 



One species only is known, which is confined to the northern part 

 of the Pacific Ocean, f 



FAMILY II. 



CETACEA ORDINARIA. 



The Ordinary Whales are distinguished from the preceding by the 

 singular apparatus from which they have received the name of Blowers. 

 (Souflfieurs). As a large quantity of water passes into their huge mouths 

 along with their prey, some way was necessary by which they could get 

 rid of it; accordingly, it passes through the nostrils by means of a peculiar 

 disposition of the velum palati, and is accumulated in a sac situated at the 

 external orifice of the cavity of the nose, whence, by the compression of 

 powerful muscles, it is violently expelled through a narrow opening on the 

 top of the head. It is in this way they produce those jets d'eau observed 

 by navigators at so great a distance. Their nostrils, continually bathed 

 by waves of salt water, could not be lined with a membrane sufficiently 

 delicate to enable them to detect odours, and accordingly, they have none 

 of those projecting laminae found in the nasal cavities of other animals; 

 the olfactory nerve is absent in several, and if there be any which enjoy 

 the sense of smell, they must have this nerve mostly in an obliterated 

 state. Their larynx, of a pyramidal form, penetrates into the posterior 

 nares to receive air and conduct it to the lungs, without compelling the 



• Rytina, wrinkled, 

 t Nov. Comm. Petrop. II., 294, et seq. It has never been figured. 



