PLATE XIII. 



Fig. 1. Deepanacanthus gemmattjs. Side view 



1 a. Section. 



1 b. Tubercles, enlarged. 



2. Base of another specimen. 



Fig. 8. Ctenaoanthtjs graoillimus. Side view 



3 a. Medial section. 



3 b. Basal section. 



4. Bone of a fish, from Burlington group, Quincy, Illinois. 



PAGB 



..123 Kto ^l//s 



.126 S f ■ LoU '£ 



