48 



Guide to the Invertvhrata. 



GALLERY triquetra, Gervillia JBronni, from the Coralline Oolite ; Alaria 



West side ^^^P^^^^^ ^^^ Pachyrisma grandis, from the Great Oolite ; Pleuro- 



tomaria (represented by many species), Amherleya Orhignyana, 



Fig. 87. 



Pleurotomaria Quoyana, F. & B. 



Recent : West Indies. 



Pleurotomaria platyspira, D'Orb. 

 Mid. Lias : France. 



s marks the position of the slit; the band which encircles the whorls of the 

 shell marks the earlier portion of the slit, now filled up by shell -growth. 



JSferitopsis Baugieriana, Pinna ampla, Trichites undata, Trigonia, 

 Astarte, and Pholadomya, -of which there are many species, from 



Fig. 89. — Sippopodium ponderosum, Sby. 

 Lias : Gloucestershire. 



Fig. 90. — Gryphcea incurva, Sby. 

 Lias : Lyme Regis. 



the Inferior Oolite^; Grypht^a incurva (T'ig. 90), Oxytoma cygnipes, 

 Sippopodium ponderosum (Fig. 89), Cardinia Listeri, Pleurotomaria 

 anglica, from the Lias. 



^ A series of Inferior Oolite Gasteropoda is temporarily arranged in a small 

 table-case in the centre of this Gallery near Table -case 92. 



