L30 PALAEONTOLOGY OF ILLINOIS. 



Genus CTENOPTYCHIUS, Ag. 

 Ct. semicircular is, N. and W. Coal Measures. 



Genus ANTLIODUS, N. and W. 



A. robustus, N. and W. Sub-carboniferous. 

 A. rnucronatus, N. and W. Sub-carboniferous. 

 A. parvidus, N. and W. Sub-carboniferous. 

 A.jsimilis, N. and W. Sub-carboniferous. 

 A. cucidlus, N. and W. Sub-carboniferous. 

 A. politus, N. and W. Sub-carboniferous. 

 A. minutus, N. and W. Sub-carboniierous. 

 A. simplex, N. and W. Sub-carboniferous. 

 A. sulcatus, N. and W. Sub-carboniferous. 



Genus DACTYLODUS, N. and W. 



D. princeps, N. and W., (type) . Sub-carboniferous. 

 D. lobatus, N. and W. Sub-carboniferous. 

 I), inflexus, N. and W. Sub-carboniferous. 



Genus POLYRHIZODUS, McCoy. 



P. porostts, N. and W. Sub-carboniferous. 

 P. dentatus, N. and W. Sub-carboniferous. 

 P. ponticulus, N. and W. Sub-carboniferous. 



Genus CHOMATODUS, Ag. 



Ch. gracillimus, N. and W. Sub-carboniferous. 

 Ch. cultellus, N. and W. Sub-carboniferous. 

 Ch. pumllus, N. and W. Sub-carboniferous. 

 Ch. affinis, N. and W. Sub-carboniferous. 



