CLASSIFICATION OF ANIMALS. 337 



X. Cetacea, whales ; living entirely in the sea, and formed like 

 fishes ; breathe by an opening at the top of the head, called the 

 blowing-hole ; through which they throw out the water, which enters 

 their moulh with the food. Smooth skin covering a thick layer of 

 oily fat. No external ear. A complicated stomach. Multilobu- 

 lar kidneys, larynx of a pyramidal shape, opening towards the blow- 

 ing-hole. Testes within the abdomen. Mammae at the sides of the 

 vulva. Bones of the anterior extremity concealed and united by 

 the skin, so as to form a kind of fin. 



1 Mouodon, narwhal, sea-uni- 3 Physeter 



corn 4 Delphinus, dolphin, porpoise 



2 Balama, proper whales 



Cuvier distributes the class mammalia into three grand divisions : 



1. Those which have claws or nails (mammiferes a onglts) ; in- 

 cluding the following orders : bimana, quadrumana, cheiroptera, 

 plantigrada, carnivora, pedimana, rodentia, edentata, tardigrada. 



2. Those which have hoofs (mammif. a ongles) ; including the 

 pachydermata, ruminantia, and solipeda. 



3. Those which have extremities adapted for swimming {mammif. 

 a pieds en nageoire). Amphibia and cetacea. 



Birds are oviparous ; have a single ovary, and oviduct ; a single 

 occipital condyle ; a very large sternum ; and anterior extremities 

 adapted for flying. 



They have three eyelids ; no external ear ; a cochlea conical, but 

 not spiral; a single ossiculum auditus ; body covered with feathers. 

 The lungs are attached to the surface of the chest; and penetrated 

 by the air, which goes all over the body : there is a larynx at each 

 end of the trachea ; no epiglottis. The jaws are covered with a 

 horny substance. The chyle is transparent ; no mesenteric glands ; 

 nor omentum. No bladder of urine ; the ureters terminating in a 

 bag, through which the eggs and faeces come, viz. the cloaca. 



This class cannot be distributed into orders so clearly distinguished 

 by anatomical characters as the preceding one. Blumerbach divides 

 them into two leading divisions. 



(A) Terrestrial Birds. 



Order I. Accipitres, birds of prey, with strong hooked bills, and 

 large curved talons, a membranous stomach, and short caeca. 

 vol. v, z 



