"9 
PLATE XX. 
Zone of Aegoceras angulatum. 
Fig. 1, Aegoceras Charmassei, d'Orhigny, Side view, natural size: together with a 
very accurate tracing of the compH- 
cated lobe-Kne, showing the lobes and 
saddles in situ on the side of this 
Ammonite. My collection from Lyme 
Regis. 
2. — — — Front view, showing sulcus on the 
siphonal area and rib tubercles there. 
3. — — — Back view of the same fossil. 
