PLATE XIX. 
Zone of Aegoceras planorhis. 
Pig. 1. Aegoceras Belcheri, Simpson. Side view, natural size. Prom the cabinet of 
the Rev. T. Wiltshire, P.G.S. 
2. — — "- — Siphonal area of the same, smooth. 
3. — TORUS, J' = Johnston I, /(Sow. Natural size. Prof. Deslong- 
champ's collection. 
4. — — — Siphonal area of same, smooth. 
5. — CATENATUM, Sowerhy . Side view, natural size. My collection. 
6. — — — Siphonal area, showing the ribbing. 
7. — — — Lobe-line, showing lobes and saddles magni- 
fied. 
8. Arietites scipionianus, (T Orb. Lateral view, natural size. My collection. 
9. — — - — Siphonal area showing deep keel. 
10. — — — Lobe-line with lobes and saddles magnified. 
