PLATK XI B— Continued. 



Fig. 19. A pygidium showing the lower surface, the extent of the doublure and the points of attachment 

 of tli'' pygidial appendages. 



i lornifei-ous limestone. Canandaigna, Ontario cowiiy. 

 Fig. 20. A p\ gidium with comparatively short spines for this species. 



Comiferous limestone. Locality • 

 Fig. 131. The axis of a pygidium. drawn from an internal cast, showing- the median depression and obso- 

 lescence of the annulations near the extremity. 



Comiferous limestone. Schoharie county. 



Dalmanites (Odontocephalus) bifidus. 



Page 53. 

 Fig. 22. A small, imperfect pygidinm, showing the extended, explanate posterior extremity and the stout 

 terminal spines. 



Comiferous limestone. Columbus, Ohio. 

 Fig. 23. Another pygidium of a young individual. 



Comiferous limestone. Lime Rock, near LeRoy, Geneiee county. 

 Fig. 24. A large pygidium, showing the normal features of this part. The crust on the original is partly 



broken away, but it has been restored in the drawing. 

 Pig. 25. The same, drawn in profile. 



Comiferous limestone. Lime Rock, near LeRoy, Genesee county. 



