LIST OF ILLUSTRATIONS XX111 



PAGE 



Fig. 4. Lepadocrinus Gebhardi Hall, T . Lower Helderberg Series, 



New York : after Hall. 

 Fig. 5. Lingulella cuneata Conrad, -\. Medina Stage, New York : 



after Hall. 

 Fig. 6. Orthis elegantula Dalman, {. Niagara Stage, New York : 



after Hall. 

 Fig. 7. Spirifera crispa Hiesinger, {. Niagara Stage, New York : 



after Hall. 

 Fig. 8. Rhynchotreta cuneata, {. Niagara Stage, Indiana : after 



Hall. 

 Fig. 9. Platyostoma niagarense Hall, j. Niagara Stage, Indiana : 



after Hall. 

 Fig. 10. Cyclonema cancellata Hall, L Clinton Stage, New York : 



after Hall. 

 Fig. 11. Capulus angulatus Hall, L Niagara Stage, New York: 



after Hall. 

 Fig. 12. Orthoceras annulatum Sowerby, |> Niagara Stage, New 



York : after Hall. 

 Fig. 13. Phragmoceras parvum H. & W., |. Niagara Stage, Ohio : 



after Hall. 

 Fig. 14. Trochoceras desplainense M'Chesney, \. Niagara Stage, 



Wisconsin : after Hall. 



Plate IV. American Devonian Fossils 401 



Fig. 1. Heliophyllum Halli E. & H., \. Hamilton Stage, Michi- 

 gan : after Rominger. 



Fig. 2. Acervularia Davidsoni E. & H., \. Hamilton Stage, 

 Michigan : after Rominger. 



Fig. 3. Spirifera pennata Atwater, |. Hamilton Stage, New 

 York : after Hall. 



Fig. 4. Athyris spiriferoides Eaton, f. Hamilton Stage, New 

 York : after Hafll. 



Fig. 5. Rhynchonella contracta Hall, f. Chemung Stage, New- 

 York : after Hall. 



Fig. 6. Pterinea fiabella Conrad, |. Hamilton Stage, New York : 

 after Hall. 



Fig. 7. Conocardium trigonale Hall, f. Corniferous Stage, Ohio : 

 after Hall. 



Fig. 8. Euomphalus Decervi Billings, \. Corniferous Stage, Ohio : 

 after Hall. 



Fig. 9. Gomphoceras mitra Hall, \. Corniferous Stage, Indi- 

 ana : after Hall. 



