146 NORTH AMERICAN INDEX FOSSILS. 



225. P. parked (Heilprin). (Fig. 1397, a.) Carbonic. 

 Subglobose, involute ; abdomen rounded ; sides somewhat flat- 

 tened; whorls high, and deeply embracing; lobes digitate; saddles 

 entire. 



Coal Measures (Strawn formation) of Texas. 



226. P. (Parapopanoceras) haugi Hyatt and Smith. Triassic. 

 Umbilicus rather wide, one fourth diameter of shell; umbilical 



shoulders abrupt; venter high, arched, helmet-shaped; surface 

 smooth ; lobes digitate, serrations running high on sides of saddles, 

 which are rounded on top. 



Middle Triassic of Inyo County, California. 



XC. Shumardites Smith. 



Subglobose, rather evolute goniatites, with highly arched whorls, 

 helmet-shaped, and deeply embracing; venter broadly rounded, 



^^ 



'\k%Ai^A 



T» 



Hfm 



YlG. 1397. a, Popanoceras parkeri, suture ; b-d, Schuynardites simondsi, sutures at 

 different stages. (After J. P. Smith.) 



sloping in a gentle curve to the abrupt umbilical shoulders; um- 

 bilicus broad and deep; surface smooth except for obscure con- 

 strictions and traces of ribs on umbilical border; septa with 

 numerous, rounded, constricted saddles and partly bifid, somewhat 

 ammonitic lobes; siphonal saddle bottle-shaped; young form gas- 

 trioceran. Carbonic. 



227. S. simondsi Smith. (Fig. 1397, Z^-c?.) Carbonic. 



Whorls twice as wide as high ; general form much as in Fig. 

 1393, J (Schistoceras hildrethi), but umbilical angle more rounded. 

 (Type of genus.) 



Cisco formation (Missourian) of Texas. 



