XX11 LIST OF ILLUSTRATIONS 



PAGE 



Plate II. American Ordovician Fossils 383 



Fig. 1. Brachiospongia cligitata Owen, ^. Trenton Stage, 



Kentucky. 

 Fig. 2. Dicranograptus ramosus Hall, ^. Utica Stage, New York : 



after Hall. 

 Fig. 3. Diplograptus pristis Hiesinger, |. Utica Stage, New 



York : after Ruedemann. 

 Fig. 4. Phyllograptus typus Hall, -J-. Calciferous Stage, Can- 

 ada, after Hall. 

 Fig. 5. Dendrocrinus polydactylus Shumard, \. Hudson Stage, 



Indiana : after Meek. 

 Fig. 6. Agelacrinus cincinnatiensis Roemer, j-. Hudson Stage, 



Ohio : after Meek. 

 Fig. 7. Orthis lynx Eichwald, {. Hudson Stage, Ohio: after Meek. 

 Fig. 8. Rhynchonella capax Conrad, {. Hudson Stage, Ohio : 



after Meek. 

 Fig. 9. Strophomena alternata Conrad, f . Hudson Stage, Ohio : 



after Meek. 

 Fig. 10. Ambonychia radiata Hall, f . Hudson Stage, Ohio : after 



Hall and Whitfield. 

 Fig. 11. Murchisonia Milleri Hall, f. Hudson Stage, New York: 



after Hall. 

 Fig. 12. Orthoceras Duseri Hall and Whitfield, f. Hudson Stage, 



Ohio : after Hall and Whitfield. 

 Fig. 13. Asaphus gigas Dekay, }. Hudson Stage, New York: 



after Hall. 

 Fig. 14. Calymene callicephala Green, f . Hudson Stage, Ohio : 



after Meek. 

 Fig. 15. Triarthrus Becki Green, f. Utica Stage, New York: 



after Hall. 

 Fig. 16. Trinucleus concentricus Eaton, \. Hudson Stage, New 



York : after Hall. 

 Fig. 17. Leperditia fabulites Conrad, |. Trenton Stage, Minne- 

 sota : after Ulrich. 



Plate III. American Silurian Fossils 392 



Fig. 1. Astylospongia praemorsa Goldfuss, ^. Niagara Stage, 



Tennessee : after Roemer. 

 Fig. 2. Graptolithes clintonensis Hall, {. Clinton Stage, New 



York : after Hall. 

 Fig. 3. Favosites Forbesi E. & H., {. Niagara Stage, Indiana: 



after Hall. 



