PLATE XXII. 



PAGE 



CTENACANTHUS DEFLEXUS, St. J. and W 234 



Fig. 1 a. Side-view of spine, outline partially restored; 1 b, do., showing the anterior 

 edge: 1 c, do., posterior face; 1 d, e, do., transverse sections near the 

 inferior angle of the posterior face and near the broken upper extremity. 

 St. Louis; Alton, 111., Mr. Alex. Butters. 



CTENACANTHUS BUTTEKSI, St. J. and W 240 



Pig. 2 a. Dorsal view of spine; 2 b. do., view of right side; 2 c, do., showing posterior 

 face; 2d, do., cross sections from the middle and near the extremities; 

 2 e, do., enlargement showing tuberculated costse in the basal angle in 

 front, somewhat worn. Lower Coal Measures, Coal No. 5; Carlinville, 

 111.. Mr. Butters. 



