178 



A CLASSIFICATION OF THE VERTEBHATA. 



f Phylum Vertebrata or Chordata* 



r^ f Sub-phylum Enteropneusta or Hemichorda (Balanoglossus, 



Cephalodiscus, Rhabdopleura). 



v*j 



S -g '. Sub-phylum Tunicata or Urochorda (Tunicates or Ascidians). 



II 



**!'' (^Sub-phylum Cephalochorda (Branchiostoma or Amphioxus). 



a 



f Sub-phylum Craniata. 



Division Cyclostomata or Round Mouths. Without 

 true jaws. (Lampreys and Hagfish.) 



Division Gnathostomata. With true jaws. 



Sub-division Anamnia (Embryo without an amniou 

 or a functional allantois). 



Ichthyopsida f Class Pisces (Fishes). 

 (Fishes and < 

 An,,,ini,ian S ). ^ class Amphibia (Newts, Progs). 



Sub-division Amniota (Embryo with an amnion 

 and an allantois). 



Class Reptilia (Lizards, Snakes, Tor- 

 (jSFSSi J toises ' Crocodiles). 

 J Class Aves (Birds). 



Class Mammalia (Mammals). 



