Su/)c'ar()oiii/frnus and Carbo)ii fcrous Cephalopoda. 167 



to the margin of the roimded dorsum. Our specimen shows 

 only the septate portion, and hence the 1)ody chamber and 

 aperture are unknown. 



Septa very close, crowded, sinuous. Dorsal lobe narrow, 

 twice as long as wide, linguiform; dorsal saddles a little 

 wider than the dorsal lobe, quite as long, linguiform ; superior 

 lateral saddle broader than the dorsal, gradually contracting 

 and rounded at the extremity ; lateral lobe obtusely angular. 



The thin, discoidal, flattened form, depression at the superior 

 lateral saddles, and sinuosities of the septa will distinguish 

 this from all other described species. 



Found in the St. lyouis Group, at Crab Orchard, Kentucky, 

 and now in the collection of Charles Faber. 



GoNI.VTITEvS LEVICULUB, U. sp, 



Plate 6, Fi^ii'. 10, lateral vieiv, natural size ; Fig. 11, dorsal I'iezv, 

 shoxcing the septa on the dorsuui and an end viezv. 



vShell very small, discoid, broadly rounded on the side and 

 dorsum forming about half an ellipse from the margin of the 

 umbilicus on one side to the margin of the umbilicus on the 

 other, and consisting of many volutions. Umbilicus large, 

 abrupt, deep or open, and exposing very little of the inner 

 whorls. Volutions numerous (four are visible in the speci- 

 men illustrated, and as many are seen in a much smaller speci- 

 men), very slowly enlarging, the outer ones profoundly 

 furrowed fur the reception of the inner ones ; transverse 

 diameter of the inner whorls greater than the dorso-ventral, 

 but toward the aperture the dorso-ventral diameter exceeds 

 the transverse. Our specimens show only the septate portion 

 of the shell, and consequently the body chamber and aperture 

 are unknown. 



Septa close and moderately sinuous. Dorsal lobe about as 

 wide as long, and arcuate at the extremity; dorsal saddles 

 rather narrower than the dorsal lobe and sublinguiform, but 

 spreading over the lateral borders ; lateral lobe very obtuse, 

 the septa in a side view being somewhat sigmoidal. 



The form, great number of volutions, and character of the 

 septa, will distinguish this from all other described species. 



Found in the St. Louis Group, at Crab Orchard, Kentucky, 

 and now in the collection of Charles Faber. 



