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 Embryology and Anatomy) 



Ancestral Elasmobrancli 



Protoganoid 



BoaA CSO) 

 (On Circulatory System) 



Dipnoan 



Teleost 



Gill ('95) 

 (On Structural Characters) 



CiintherCSO)* 



(On Anatomy) 

 Includes Lancelet and Cyclostomes 

 as 2 Sub classes of Fishes 

 Palaeiehthys 



Ganoid 



Amphibia 

 Protopterus 



Ceratodus 



\ Teleosls 



Ganoids 

 (With Dipnoans) 



Chondrosteans 



(Sharks and Chimaeroids) 



Myxin 

 Petroniyzon' 



Chimaeroid 



s.Teleostome 

 ^ Dipnoan 

 Elasmobranch 



DavldoffCSO) 



(On Extremities and Girdles) 



Primitive Gnathostome 



Bridge CrS) 

 (On Osteology of Ganoids) 



Scaphyrhynchus 



I 



Acipenser 



Apneumato- — 

 coela 



Elasmobranch 



Polyodon 



Selachian 



I ' 1 



Shark RaysC?) 



I "^"^ Chimaeroid 



HeptanSus Aclnthij 



.Pneumato- 



coela 



Polypterus 



Amia 



Selacboidei 



Teleosteoidei 



Amphibia 



Lepidosteus 

 I 



Dipnoi 



Phy SOS tome 



RaM C89) 

 (On Embryology) 



A 



Cyclostomes Amphioxus 



Beard ('90) 

 (On Embryology and Brain) 



Selachians 



/, 



Sel ach od i ch th y idae 



Selachians 



Ganoids 



DStS \t 



Pollard ('91) 



(Ou Auatomy of Head) 



\ Shark 



Crossopterygian 



Ctenodipterini 

 (Devon) 



Amphibia 



Teleosts \Ampliibia 

 and Protamnia 



Ischyodus 

 (Jura) 



Holocephali 



Ceratodus 

 (Trias) 



Ceratodus 



Protopterus 



Dipnoaus and 

 Amphibia 



