582 MOLLUSCA SUB-KINGDOM VI ’ 
lobes, the outer or second pair being incomplete in the more discoidal species as j 

Aspidoceras perarmatum, Sowb. sp. Oxfordian; Dives, Cal- Lower Tithonian ; Monte Catria, 
vados. 1/y, Central Apennines. 
in Arietidae. Siemiradzkia Wears resemblance in the young or throughout life to 
Perisphinctes. 
Aspidoceras, Zittel (Fig. 1215); Peltoceras, Waagen (Fig. 1216); (2?) Awrigerus, 
Oppel; (2) Simoceras, Zittel (Fig. 1217); Stemiradzkia, gen. nov. Type S. (Amm.) 
‘Ne 4 J PR > 
Ma tf; ‘ 
Ga} € q a Teele Wi Be i Hy P- 2 Pe) 
t i. oy Wie. Wee 
Ba a NH g 
Z : « TASS Fi), , S 
g Pans We j Vase ke 
g . €.5 / WA 7 
E 5 : =: . ADT > ¥, a : : 
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Fic. 1217. 
1G. 1915 ; a 
Fie. 1210. Simoceras Volanense, Oppel sp. 

spinosum, Oppelsp. Upper 
Jura; Swabian Alps. 1/9. 

Fic, 1216. 
Peltoceras athieta, Phill. sp. Upper Callovian; Vaches noires, 
Normandy. 1/}. 
Fic, 1218. 
Physodoceras circum- 
Bakeriae, VOrb. sp. (Terr. Jurass, Pl. 149, Fig. 1 non Pl. 148]. Physodoceras, gen. 
nov. (Fig. 1218). Type P. (Amm.) cirewmspinosum, Oppel sp. Upper Jura. 
