ISO 



NORTH AMERICAN INDEX FOSSILS. 



XCV. Medlicottia Waagen. 



Discoidal, highly involute shells, with a narrow, grooved venter 

 and smooth surface ; suture ammonitic, with numerous narrow 

 lobes and saddles, the latter rounded and entire or with lateral 

 incisions, the lobes divided ; siphonal lobe deep, bounded by high, 

 much notched, external saddles. 



Permic of India, Ural Mountains, Sicily and Texas. 

 236. M. copei White. (Fig. 1400, a-c.) Permic. 



Fig. 1400. a-c, Medlicoitia copei ; d, e, Waagenoceras cumminsi ; f, PV. Ai/h', suture. 

 (After J. P. Smith.) (All X %, except sutures. ) 



Siphonal lobe narrow, with numerous notches; external saddles 

 much notched, the others simple; ventral furrows bounded by 

 angular and slightly beaded keels. 



Wichita formation of northern Texas. 



Nannitida. 

 XCVI. Nannites Mojsisovics. 

 Subglobose, rather involute shells, with highly arched, helmet- 

 shaped whorls, open, deep umbilicus with steep umbilical shoulders 



