204 PHILOSOPHY OF ZOOLOGT. 



Without the rudiments of claws. 



116. Halicora. Dugong. Grinders, twelve in num- 

 ber, three on each side. Two incisors above, and the vesr 

 tiges of several small ones below. The structure of H. 

 Indica, the only well established species, has recently been 

 ably unfolded by Sir E. Home, in the three paperi^ 

 which he has communicated in the Philosophical Trans- 

 actions for 1820, Part. II., with finished delineations by 

 Mr Cliff. 



117. Rytina. Syren. One grinder on each side. 

 Lips whiskered. The only ascertained species of this ge- 

 nus inhabits the north-western coasts of America. 



This singular group of herbivorous apodal mammalia 

 probably consists of many more species than those which 

 have hitherto been described. 



CETACEA. 



Nostrils opening on the crown of the head. 



The skin is smooth and glossy. The cuticle resembles 

 a piece of oiled silk cloth, and the corium is thick, and 

 consists of vertical fibres. The stomach is complicated. 

 The larynx forms a tabular projection across the pha- 

 rynx into the canal of the nose *. The bronchial termina- 



from which a considerable quantity of oil was obtained." Mr Stewart has 

 since informed me, that it came ashore at Newhaven, in the harvest season. 

 Though it had been dead for some time, and was in a putrid state, he was 

 able to satisfy himself with regard to the species. 



• When whales come to the surface to respire, they produce a hissing 

 noise, and a column of vapour arises, sometimes to a considerable height. 

 When expiration happens to take place, before the head has actually reached 

 the surface of the water, some spray may also he thrown up. This, how- 

 ever, is seldom the case ; hence the term blow-holes, instead of spout-holes, 

 to express the nostrils, is more appropriate. The term nostril, indeed, may 



