142 



NORTH AMERICAN INDEX FOSSILS. 



213. G. striatus Sowerby. (Fig. 1393,1-/.) Mississippic. 

 With strong and sharp, revolving striae, and sharply incised sin- 

 uous cross strise. 



St. Louis-Chester of Arkansas (Fayetteville shales) ; Bend of 

 Texas. 



214. G. subcircularis Miller. (Fig. 1393, w-o.) Mississippic. 

 More compressed than preceding, with larger umbilicus, and 



coarser spirals without crenulations ; four deeply incised constric- 

 tions to the whorl, bending sharply forward on the venter. 

 St. Louis of Kentucky; Fayetteville shale of Arkansas. 



LXXXV. Glyphioceras Hyatt (emend. Haug). 



Goniatites of moderate involution, open umbilicus, rather broad 

 and low whorls of semilunar or trapezoidal section and fine lateral 



Fig. 1391. a-c^ Glyphioceras calyx^ shell about X 7> ^^^ suture much enlarged ; 

 d-fy Gastrioceras branneri, shell X /^> ^"^ suture enlarged ; g, h, G. carbonarium^ 

 shell X H> a"d suture enlarged. (All after J. P. Smith.) 



or umbilical ribs ; siphuncles small and funnels generally diplo- 

 choanitic; lobes and saddles rounded. Mississippic. 



