Coccosteus 



Blastoid 

 (Eleacrinus) 



Ostraco- 



derm 



(Drepanas- 



pis) 



Terataspis 



Ammonoid 

 (Gephyro- 

 ceras) 



Pterichthys 



Profitus Pephricaris 



DEVONIAN PERIOD [To face page ^?. 



