334 



Explanation of the Plates. 



CONOCEPHALITES SHUMARDI. 



Fig. 19. A movable cheek, referred with some hesitation to this species : from Marine mills. 

 " 32. Part of the glabella and fixed cheeks restored in outline from other specimens. This is 

 the largest individual seen. 



CONOCEPHALITES WISCONSENSIS. 



Fig. 22. Glabella, frontal limb, and part of fixed cheeks ; the glabella showing indistinct furrows. 

 " 23. Profile of the same. 



" 24. A pygidium associated with the preceding specimens. 

 " 27. A smaller individual, not showing glabellar furrows. 

 " 28. A profile of the same. 



CONOCEPHALITES HAMULUS. 



Fig. 25. The glabella, frontal limb, and part of fixed cheeks ; with a slender spine from the 

 occipital ring. 

 " 26. A profile of the same. 



CONOCEPHALITES ANATINUS. 

 Fig. 29. The glabella and fixed cheeks of a small individual, from Trempaleau. 



CONOCEPHALITES PERSEUS. 



Fig. 33. Glabella and fixed cheeks of a small specimen from Kickapoo. The figure is twice 

 enlarged. 



