Gasteropoda and Lamellibranchiata. 47 



and Alaeitd^ among the Gasteropods and the NucuI(B and GALLEEY 

 Inocerami (Lamellibranchs) are most interesting. West Side. 



Fig. 85 — Inoceramus sulcatus, Park. Fig. 86. — Neithea quinquecostata, Sby. 

 Gault : Folkestone. Lower Chalk : Lewes, Sussex. 



In the next case are the Lower Greensand (Aptian), Urgonian, 

 and ITeocomian Mollusca from Punfield, Atherfield, Tealby, 

 Speeton, etc. Some fine examples of Exogyra sinuata may be Table- 

 seen (one in section shows the great thickness of the shell ^^^^ ' 

 produced by age). Another striking form is the large Pecten 

 cinctiis from the Tealby beds, Lincolnshire ; Cucullcea Gahrielis, 

 from the Atherfield beds, is also of great size. Of the Gasteropods 

 may be named Vicarya Pi%cuetana, Ceratosiphon Fittoni, etc. 



The fluviatile shells of the Wealden (!N'eocomian) include many 

 examples of the genus Unio, the largest being the Unio valdensis 

 from Sussex and from Brook Point, Isle of Wight. In the centre Table- 

 of the gallery is placed a fine slab of " Petworth Marble," entirely ^*^® ^^• 

 composed of the shells of a fresh-water snail, Viviparus {Paludina) 

 fluviorujn, Sby. The elegant columns of the Temple Church, 

 Fleet Street, are made of this marble from the Weald of Sussex. 



Jurassic Mollusca. — The British Jurassic shells occupy Table- Table- 

 cases 91-96. Many of them are figured specimens and illus- ^^^\ 

 trate the works of Phillips, Morris and Lycett, Damon, 

 Hudleston, and others. Some of the genera, such as Astarte, 

 Lima, etc., attained a large size when compared with their 

 living representatives. Among the most striking specimens are 

 Pecten lamellosus and Trigonia gihhosa, from the Portland beds ; 

 Astarte Hartwellensis and Pleurotomaria reticulata, from the 

 Kimeiidge Clay ; Bourguetia striata, NerirKza GoodhalU, Trigonia 



