152 NORTH AMERICAN INDEX FOSSILS. 



bilicus ; surface with fine, radial folds ; suture ceratitic, with short, 

 rounded and notched lateral lobes, except the adventitious lobes 

 near the venter and the auxiliaries which are goniatitic. Triassic. 



239. A. acutus Hyatt and Smith. (Fig. 1401,^-f.) Triassic. 

 Height of last whorl nearly three fifths total diameter; radial 



folds visible near the umbilicus. 



Meekoceras beds (Lower Triassic) of Idaho and Inyo Range of 

 California. 



XCIX. Sageceras Mojsisovics. 



Discoidal, involute, laterally compressed, with narrow umbilicus, 

 thin and deeply embracing whorls, rapidly increasing in size ; venter 

 narrow, furrowed and bounded by sharp ridges ; surface with lines 

 of growth and fine spirals ; saddles- numerous, long, narrow and 

 tongue-shaped; lobes bifid, increase in size gradual and regular. 

 Triassic. 



240. S. gabbi Mojsisovics. (Fig. 1402, a-c.) Triassic. 

 Very flat, with narrow, channeled venter, and abruptly rounded 



umbilical shoulders. 



Middle Triassic of Nevada. 



C. PsEUDOSAGECERAS Dieucr. 



Like the preceding but with more complex septa, the lobes partly 

 trifid; umbilicus closed. Triassic. 



241. P. intermontanum Hyatt and Smith. (Fig. 1402, J-/.) 



Triassic. 



Venter very narrow, with small furrow, bearing when perfect, a 

 central keel; saddles entire, lobes mostly bifid with lateral notches 

 but with the fifth deeply trifid. 



Lower Triassic, Meekoceras beds of Idaho, and California, also 

 Columbites bed of Idaho. 



Ceratitoidea. 



CI. Paralecanites Diener. 



Evolute, slightly embracing shells, with low whorls, and gonia- 

 titic sutures ; surface almost without sculpture ; ventral lobe divided, 

 a superior and second lateral but no auxiliary lobe. Permic- 

 Triassic. 



