No. 89.] 



103 



GONIATITES BICOSTATUS. 



The Goniatites hicostatus of the Por- 

 tage group ( Report 4th Geol. District, 

 page 245, f.8) differs from all the pre- 

 ceding species in the character of its 

 septa, which are abruptly bent along 

 thedorso-lateral groove; making, how- 

 ever, a much less angle than in G. oweni 

 or G. patersoni. 



Goniatites bicostatus. 



NAUTILUS (DISCITES) ORNATUS (n. s.)- 

 Shell discoid; umbilicus broad : volutions, three, four or more, not embracing, 

 rapidly expanding, flattened upon the dorsum and ventrum ; sides moderately 

 convex ; section and aperture quadrangular, with the ventral side the broader : 

 dorsal angles subcarinate, nodose; nodes elongate, sometimes regularly alterna- 

 ting, having one upon one division and two upon the next. Septa simple; outer 

 chamber very large. Siphuncle dorsal. 



This is a strongly marked species, and readily distinguished from the Goktia- 

 TiTES by the flattened dorsum and great width of the ventral side; and also by 

 the nodose angles, which are partially preserved even in the casts. A large speci- 

 men measures about six inches across the disc, and of this the aperture measures 

 one-half. There seems no safiicient reason for separating the species from Nauti- 

 lus, unless it be the position of the siphuncle. In thi^ respect it corresponds with 

 DisciTES of M'Coy; but as this name has been anticipated by De Haan for a 

 genus of Cephalopoda, there is an impropriety in following the latter name. 



Geological formation and locality. In the Goniatite limestone of the Marcellus 

 shale : near Manlius, and' at Schoharie. 



21 22 



DiSCITES ORNATUS. 



Fig. 21. Lateral view. 



II0.22. Profile and form of lopta. 



