IX 



THE HISTOEY AND SCOPE OF ZOOLOGY 



387 



Phylum 

 VERTEBRATA 



Branch a. 

 Hemichorda 



Branch h. 

 Ueochorda 



Branch c. 

 Cephalochorda 



Branch d. 

 Craniata 



Class. 



\ Sole Genus — Balanogkmuii. 



[" Grade a. Larvalia. 

 I 1. APPENDICULAR!^. 

 \ Grade h. Saccata. 



1. ASCIDIACEA. 



2. THALIACEA. 



Sole Genus — Amphioxus. 



Grade a. Cyclostoma. 



1. MYXINOIDEA. 



2. PETROMYZONTIA. 

 Grade h. Gxathostoma. 



Sub-Grade 1. Branchiata 

 Heterodactyla. 



1. PISCES. 



2. DIPNOI. 

 Sub-Grade 2. Branchiata 



Pentadactyla. 

 1. AMPHIBIA. 

 Sub-Grade 3. Pentad actyla 



LiPOBRANCHIA. 



Branch a. Monocondyla. 



1. REPTILIA. 



2. AVES. 



, Branch h. Amphicondyla. 

 Ll. MAMMALIA. 



THE END 



Printed by R. & R. Claric, Edinburgh. 



