CEPHALOPODA— ORTHOCHOANITES. 6 1 



Agoniatite limestone of the Marcellus of New York, etc. 



XIV. KiONOCERAS Hyatt. 

 Orthoceracones and cyrtoceracones with longitudinal ridges in 

 earlier stages (sometimes persistent), followed by inconspicuous 

 annuli which mostly disappear again in the adult. Siphuncle often 

 faintly nummuloidal. Siluric-Carbonic. 



49. K. angulatum (Wahl). (Fig. 1265.) Siluric. 



Wf 



;f}r 



Fig. 1265. Kionoceras angulatum, 

 X Vz' (After Hall, 20th State Mus. 

 Rep.) 



Fig. 1266. Kionoceras orus, X %' 

 (After Kindle, 28th Ann. Ind. ) 



Annulations faint or almost absent; longitudinal ridges strong 

 and distant. 



Niagaran of Wisconsin and Illinois. 



