I 



NEW YORK STATE MUSEUM 



Family cycloceratidae 



Genus protocycloceras Hyatt 



Protocycloceras lamarcki Billings (sp.) 



P. whitfieldi sp. nov. 



P. (?) cf. fuftivum Billings (sp.) 



Genus spyroceras Hyatt 



Spyroceras clintoni Miller (sp.) 



Genus orygoceras gen. nov. 



Orygoceras cornu-oryx Whitfield (sp.) 



Division II. PLECTOCERATIDA 

 Family tah i > 1 1 ycekatida 



Genus barrandeoceras Hyatt 



Barrandeoceras natator Billings (sp.) 



Genus eurystomites Schroder emend. Hyatt 

 Eurystomites kelloggi Whitfield (sp.) emend. Schroder 

 E. accelerans sp. nov. 

 E. amplectens sp. nov. 

 E. rotundus Hyatt 

 E. virginianus Hyatt 



Genus tarphyceras Hyatt 

 Tarphyceras farnsworthi Billings (sp.) emend. Hyatt 

 T. seelyi Whitfield (sp.) 

 T. champlainense sp. nov. 

 T. perkinsi Whitfield (sp.) 

 T. clarkei sp. nov. 

 T. multicameratum sp. nov. 



Genus aphetoceras Hyatt 

 Aphetoceras farnsworthi Billings (sp.) emend. Hyatt 

 A. attenuatum Hyatt 



Genus deltoceras Hyatt 

 Deltoceras vaningeni sp. nov. 



Family trocholitidae 

 Genus schroederoceras Hyatt 

 Schroederoceras eatoni Whitfield (sp.) 

 S. cassinense Whitfield (sp.) 



Genus trocholitoceras Hyatt 

 Trocholitoceras walcotti Hyatt 



Genus trocholites Conrad emend. Schroder 

 Trocholites internestriatus Whitfield (sp.) 



Family plectoceratidae 



Genus plectoceras Hyatt 

 Plectoceras jason Billings (sp.) 



