582 MOLLUSCA SUB-KINGDOM vi 



lobes, the outer or second pair being incomplete in the more discoidal species as 



Aspidoceraa perafmatv/m, S<nvb. sp. Oxfordian ; Dives, Cal- 

 vados, i/.i. 



FIG. 1217. 



Simocerus Volanense, Oppel sp. 

 Lower Tithonian ; Monte Catria, 

 Central Apennines. 



in Arietidae. Siemiradzkia bears' resemblance in the young or throughout life to 

 Perisphinctes. 



Aspidoceras, Zittel (Fig. 1215); Peltocems, Waageu (Fig. 1216); (?) Aurigerus, 

 Oppel; (?) Simoceras, Zittel (Fig. 1217); Siemiradzkia, gen. nov. Type S. (Amm.) 



Normandy. 



FIG. 1216. 

 I'thliti/, Phill. sp. Upper Callovian ; Vaches noires, 



FIG. 1218. 



P l> </nodoce r a s ci r c >/ nt- 

 spinosum, Oppel sp. Upper 

 Jura ; Swabian Alps. ] /"- 



Bakeriae, d'Orb. sp. [Terr. Jurass. PL 149, Fig. 1 non PI. 148], Phijsodoceras, gen. 

 nov. (Fig. 1218). Type P. (Amm.) circumspinosum, Oppel sp. Upper Jura. 



