SOME NEW DEVONIC FOSSILS 



183 



though none of this type has been described from the Helder- 

 bergian fauna yet representatives are known to occur therein, and 

 in the Oriskany of Glenerie we have the multispinous shell P. 



Platyceras paxilHfer 



nodosum Conrad and P. subnodosum Hall, which usually 

 appear in the form of nodate casts. 



In the Onondaga limestone fauna are P. dumosum, echi- 

 natum, multispinosum, fornicatum but among them 

 all is none of the type expressed in P. p a x i 1 1 i f e r . 



Lower Devonic. Grande Greve, P. Q, 



Platyceras guesnini nov. 



Shell of medium size, suberect, subsymmetrically coiled; apex 

 deeply coiled in horizontal plane, rapid expansion beginning at 

 one and one half volutions, body whorl irregularly expanded, sub- 

 circular in cross-section, direct and unattached for one half its 



Platyceras guesnini 



length. Surface without revolving furrows and ridges, and marked 

 with subequidistant concentric undulating fringes gradually be- 

 coming obsolete near the aperture; also traversed longitudinally 

 by very fine revolving lines. 



Loiver Devonic. Perce rock, P. O. 



