281 



CHAPTEE XI. 



CHOED ATA — Continued. 



The Chaeacters of Craniote or Vertebrate Animals. 



The remaining divisions of the Chordata — namely, the Fish 

 (Pisces), Frogs, &c. (Amphibia), Snakes, &c, (Eeptilia), Birds 



T> D. 



Fia. 147 — DiAGEAMMATIC SECTIONS OF AN INVERTEBRATE AND VERTEBRATE. 



D, Dorsum ; v, venter ; ff, haemal or blood system ; Be, body cavity ; B«j, body wall ; 

 G, gut ; Nc, nerve chord ; Ne, neural canal ; N^ notochord ; P, pericardium. 



(Aves), and Quadrupeds (MammaKa) — are known as Craniota 

 or true Vertebrate animals. Although, these two great sub- 

 kingdoms, the Invertebrata or Achordata and the Chordata or 



