SUPPOSED DESCENT OF GROUPS 



283 



OF THE GROUPS OF FISHES 



observers ; their views have been based on the different lines of investigation 

 interpretation of the text of the author cited. 



Balfour ('80) 

 (On Embryolo^' and Anatomy) n<Aei\ 



Ancestral Elasmobrancli ^Qn Circulatory System) 



Bony Ganoids 



Dipnoan Ganoid 



Teleost 



Gill ('95) 



(On Structural Characters) 



Amphibia 

 Protopterus 



Ceratodus 



Giinther ('80)* 



(On Anatomy) 



Includes Lancelet and Cyclostonies 

 as 2 Sub classes of Fishes 



Palaeichthys 



\ Teleosts 



Ganoids 

 (With Dipnoans) 



Chondrosteans 



(Sharks and Chimaeroids) 



Myxiue 

 Petromyzon 



Chimaei'oid 



Pleuracanthid 



.Teleostome 

 Dipnoan 

 Elasmobranch 



Davldoif('80) 



(On Extremities and Girdles) 



Primitive Gnathostome 



Bridge ('78) 

 (On Osteology of Ganoids) 



Scaphyrhynchus 

 Acipenser 



Apneumato- — 

 coela 



Elasmobranch 



I 



r 



Selachian 

 I 



Selachoidei 



Teleosteoidei 



Shark Rays(?) 



Poly'odon | "^ Chimaeroid 



Heptanchus ^nthias 



.Pneumato- 

 coela 



Polypterus 

 ' 



X. 



Amia 

 I 



1 



Lepidosteus 



I 



Dipnoi 



Physostome 



Kabl ('89) 

 (On Embryology) 



Cyclostomes Amphioxus 



Beard ('90) 

 (On Embrj'ology and Brain) 



Selachodichthyidae 



Selachians 



Ganoids 



Teleosts XAmpTiibia 

 and Protamnia 



Ischyodus 

 (Jura) 



Pollard ('91) 



(On Auatomy of Head) 



j \sharic 

 Crossopterygian 



Ctenodipterini 

 (Devon) 



Amphibia 



Selachians 



Ceratodus 

 (Trias) 



Ceratodus 



Dipnoans and 



Amphibia 



Holocephali 



Protopterus 



