Plate VI. 



Page 

 Fig. 1 -2. Sjirinyopora sp., showing size and outer form of the corallites in 



tninsviT.se and longitudinal section 15 



Fig. J{. Fauosites cf. helderbergiae HAM., longitudinal section, showing the 



closely arranged tahulae, X 2 11 



Fig. 4. Tltecia stvinderenana GOI.DF., part of the surface, X 2 15 



Fig. fi 7. Concliidinm arcticutn nov. sp. from Series A, east coast of North Devon 5 

 Fig. 5. A fragment of a strongly worn ventral valve showing the 



length of the median septum. 

 Fig. 6. A fragment of a dorsal valve with a line showing the convexity 



in transverse section. 



Fig. 7. Line showing the convexity of another dorsal valve in longi- 

 tudinal section. 



Cifftina yjuui nov. sp., from upper Devonian beds of Beechey Is- 

 land, Lancaster Sound 47 



