Cyclonema rugaeliiieata. 

 Fig. 21. Anterior view of a partly exfoliated specimen. Page 187 



Strophodonta demissa. 

 Fig. 22. Ventral view of a specimen. Page 148 



Spirifera dubia. 

 Fig. 23, 24. Dorsal and profile view of a specimen. Page 115 



Fentamerus uniplicatus. 



Fig. 25, 26. Dorsal view of a specimen Page 63 



Pentamerus nucleus. 

 Fig. 27-29, 31-33. A series of specimens showing variation in size. Page 59 



Flatyostoma niagarense. 

 Fig. 30. Vertical view of a young specimen. Page 185 



