FRIONOCEKAS. 59 



PrIOXOCERAS ? ANDREWSI AVillclu'll. 



1870. Gmmtite^ andnncsl, A. Wiiichrll. Proc. Am. Pliilos. Soc. Vol. XI. p. 2.5it. 



.Shell subglobose, evoliite: whorls Iji-omlcr tiuiii hi;^h, low-arched, 

 helmet-shaped, greatest width clo.sc to uiuMlical shoulder. Umbilicus 

 deep and wide, umbilical shoidders abrupt and hearing tnint ribs. Surface 

 ornamented with tour coustrictions to a revolution. 



Septa consisting ot" a long, undivided, tongue-shaped, pointed ^•entral 

 lobe, a similar but shorter and broader lateral lobe, a rather narrow club- 

 sha))ed external saddle, and a broad oblique lateral. 



Occnyyoice. — Lower Carboniferous, Kinderhook stage, Lower Waverly 

 group, Newark, Ohio. 



Prionoceras? liRowNENsE Miller. 

 PI. V, tigs. 1 and 2. 



1891. Goniatites hnyuineiiBiH, S. A. Miller, Advance sheets Seventeenth Ann. Rept. 



Geol. Surv. Indiana, p. 90, PI. XVIII, tios. 3, 4. 



1892. Goniat'deH hrownevKls, S. A. Miller. Seventeenth Ann. Rept. txeol. Surv. 



Indiana, p. 700, PI. XVIII, tios. 3, 4. 



Shell globose, evolute, broadly rounded on the venter, and rather 

 deeply embracing the outer whorls, covering about three-fifths of the inner 

 ones. Umbilicus rather wide, being about two-fifths of the total diameter 

 of the shell, and exposing all the inner wliorls. Surface of the shell 

 apparently smooth. 



Septa not distinctly made out, but consisting of a pointed ventral lobe, 

 with a pair of angular latei'als, and proliably also with a pai>- of auxiliary 

 lobes on the umbilical shoulders. The dorsal lobes correspond to the 

 external, as well as could be seen on the broken face of the wliorl. 



Occurrence. — Lower Carboniferous, Kinderhook stage, Knobstone 

 group. Brown County, Ind. 



Prionoceras? ohioense Winchell. 



1870. GoulnHtfK ohioenxis, A. Winchell, Proc. Am. Philos. Soc, Vol. XI, p. 2.59. 



Shell subglobose, umbilicated; whorl depressed, helmet-shaped, abdo- 

 men broadly arched, sides sloping steeply to the abrujit umbilicus, which 

 has diameter of more than one-half of the diameter of the shell. 



Septa consisting of a slender ventral lobe with rounded end, a first 



