510 NEW YORK STATE MUSEU:M 



Family cyclocerj^vtidae 



Genus protocycloceras Hyatt 



Protocycloceras lamarcki Billings (sp.) 



P. whitfieldi sp. nov. 



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



Genus spyroceras Hyatt 

 Spyroceras clintoni Miller (sp.) 



Genus orygoceras gen. nov. 

 Orygoceras cornu-oryx Whitfield (sp.) 



Division II. PLECTOCERATIDA 

 Family tarf»hycera.tida.e 



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. attenuatnm Hyatt 



Genus deltoceras Hyatt 

 Deltoceras vaningeni sp. nov. 



Family trocholitidj^e 

 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 plecxoceratidae 



Genus plectoceras Hyatt 

 Plectoceras jason Billings (sp.) 



