274 



PALEONTOLOGY OF THE EUEEKA DISTRICT. 



DEVONIAN. 



ABBREVIATIONS. Up. Held. = Upper Helderberg. Ham. = Hamilton Group. Ch. = Chemung Group of the Devonian 

 series of the Geological Survey of New York. H. & W. = Hall &. Whitfield, Geol. Expl. Fortieth Parallel, vol. iv, 1877. 



