106 ON ZOOLOGY. 



toads, lizards, caraelions, crocodiles, alligators, 

 and serpents. 



Fourthly, Pisces, cold red blooded animals, with 

 a single heart, which breathe through gills in 

 the place of lungs without the power of suspend- 

 ing respiration ; embracing all the perfect fishes, 

 with the exception of the whale tribes. 



Fifthly. Insecta, cold white blooded animals, 

 with an imperfect single heart distinguished from 

 worms by having antenna, or small horn like 

 processes, includingthe various species of insects, 

 and crustaceous shell fish, as lobsters, crabs, 

 shrimps, and the like. 



Sixthly. Vermes, cold white blooded animals, 



with an imperfect single heart, having tentacula 



in the place of antennae, and embracing the 



various species of worms, testaceous shell fish, 



as oysters, muscles, and the like, and zoophites. 



Each of the above classes has been subdivided 

 (as we have previously intimated,) into orders, 

 genera, and species ; but as our object has been 

 rather to explain the principle of the system than 

 to trouble you with the detail, we must refer you 

 to the several works that have been published on 

 the subject for the further particulars.* 



Cuvier, who, it appears, has directed his atten- 



* A more detailed account of Linnaeus's classification is to 

 be seen in his General System of Nature translated by Dr 

 Turton, in the smaller edition of Bingley's Animal Biography, 

 and in most of the Encyclpoedias. 



