1897.] NEW PALEOZOIC VERTEBRATA. 91 



EXPLANATION OF PLATES. 



Plate L 



Scales ofSagenodus from the Coal Measures of Mazon Creek, 

 Illinois, natural size. 



Fig. I. S.foltattcs Co'^Q XjT^Q', 2-3. S. reticulatus ^Qwh.] 4. S. 

 conchiolepis Co^Q type; 5. S. lacovianus Cope type; 6. 6". quin- 

 cunciaius Cope type; 7. 6". brownice Cope type; 8. S. magister 

 Cope type; 9. S. gurleianus Cope type. 



Plate II. 



Figs. 1-3. Scales of Holoptychius, nat. size, except Fig. 2X2. 

 Fig. I. H. serrulatus Cope type ; 2. H. latus Cope type; 3. H. 

 flabellaius Cope type. 



Fig. 4. Sauropleura latithorax Cope type, natural size. 



Plate III. 



Fig. I. Ctenerpeton foveolatum Cope, from below, natural size; 

 2. Cer aterpeton te7tidcorne Co'^e, from above, natural size; 3. Iso- 

 dectes punctulatus Cope, natural size. 



[The Secretaries deem it proper to state that when the proofs of the plates of 

 this paper were taken to Prof. Cope he was too ill to examine them, and owing 

 to his subsequent death they have been compelled to print the plates as drawn, 

 without the benefit of his correction.] 



