Lasanius 



Lanarkia 



Lasanius 



Cyathaspis 



Tremat- 

 aspis 



Nautiloid 

 (Gompho- 

 ceras) 



Lampshell 

 (Spinfer) 



.^ Hemiaspis 



Chonetes 



Sea-urchin 



(Palaeechi- 



Staurocephalus Deiphon 



SILURIAN ^MARINE LIFE [To face page ^6 



