Plate III. — Continued. 



Fig. 9. Onchus rectus Eastm. Chemung group; Delaware 

 county, New York. Dorsal fin-spine, lateral face, x 6-5. Page 150 



Fig. 10. Homacanthus acinaciformis Eastm. Chemung 

 group; Warren, Pennsylvania. Dorsal fin-spine, lateral face, 

 x 4-3. Page 151 



Fig. 11. Dinichthys pustulosus Eastm. Oneonta sandstone 

 (Portage group) ; Delhi, New York. External aspect of left 

 mandibular ramus, partly restored, x 1-2, approximately. 

 Page 194 



Fig. 12. Dinichthys pustulosus Eastm. Cedar Valley lime- 

 stone; near Eock Island, Illinois. Incomplete mandible col- 

 lected and drawn by Orestes H. St. John, and described in the 

 American Naturalist for 1902, p. 657. x 3-4. Page 194 



304 



