CLASSIFICATION OF THE ANIMALS AND GROUPS OF 

 ANIMALS MENTIONED IN THIS BOOK 



(An asterisk denotes a totally extinct group) 



Chordata. 



Hemichordata. 

 Pterobranchia, e.g. Cephalodiscus. 

 Enteropneusta, e.g. Balanoglossus. 

 Protochordata (Acrania). 

 Urochordata. 



Ascidiacea, e.g. Ascidia. 

 Thaliacea, e.g. Salpa. 

 Larvacea, e.g. Fritillaria. 

 Cephalochordata, e.g. Amphioxus. 

 Craniata. 

 Anamnia. 

 Cyclostomata. 

 Cyclostomata. 



Petromyzontia, e.g. Petromyzon 



(? Palaeospondylus). 

 Myxinoidea, e.g. Myxine, Bdello- 

 stoma. 

 Qstracoderma,* e.g. Cephalaspis. 

 Gnathostomata. 

 Pisces. 

 Chondrichthyes. 



Selaehii, e.g. Scyllium, Squalus, 

 Heptanchus, Hexanchus, He- 

 terodontus, Pristis, Rhina, 

 Pliotrema, Raia, Torpedo. 

 Holocephali, e.g. Chimaera. 

 Acanthodii,* e.g. Acanthodes. 

 Pleuracanthodii* e.g. Pleura- 

 - canthus 



Cladoselachii,* e.g. Cladoselache. 

 Osteiehthyes. 

 Teleostomi. 



Osteolepidoti * e.g. Osteolepis, 



Sauripterus. 

 Coelacanthini,* e.g. Undina. 

 Polypterini, e.g. Polypterus. 

 Palseoniscoidei,* e.g. Cheiro- 

 lepis. 

 487 



Phylum. 



Subphylum. 



Class. 



Class. 



Subphylum. 



Class. 



Order. 



Order. 



Order. 



Class. 



Subphylum. 



Grade. 



Branch. 



Class. 



Subclass. 



Subclass. 



Class. 



Branch. 



Class. 



Grade. 



Order. 



Order. 

 Order. 

 Order. 



Order. 

 Grade. 

 Subclass. 

 Order. 



Order. 

 Order. 

 Order. 



