48 



CETACEOUS FISH. Class IV, 



viz. two peroral fins, and one back fin ; but in 

 fome fpecies the lad is wanting. 



Their tails are placed horizontally or fiat in re- 

 fpedt to their bodies -, contrary to the direction of 

 thofe of all other fifh, which have them in a per- 

 pendicular fite. This fituation of the tail enables 

 them to fQrce themfelves fuddenly to the furface of 

 the water to breathe, v/hich they are fo frequently 

 conftrained to do. 



Many of thefe circumftances induced Linnaus to 

 place this tribe among his Mammalia^ or what other 

 writers ilyle quadrupeds. 



To have preferved the chain of beings entire, 

 he fliould in this cafe have made the genus of 

 Phoc^^ or Seals^ and that of the ^richecus or 

 Manati^ immediately precede the whale, thofe be- 

 ing the links that connedl the Ma?nmalia or qua- 

 drupeds with the fiih ; for the Seal is, in refped 

 to its legs, the mod imperfedl of the former clafs ; 

 and in the Manati the hind feet coalefce, afiiim- 

 ing the form of a broad horizontal tail. 



Notwithftanding the many parts and properties 

 which cetaceous fifh have in common with land 

 animals, yet there flill remain others, that in a 

 natural arrangement of the anim.al kingdom, muft 

 determine us after the example of the illuftrious 

 Ray *, to place them in the rank of nfh \ and for 



* Who makes two diWlions of filh. 



1. Puhnone refpir antes, 



2. BranchiU refpir ant ^^ 



the 





