MOLLUSCA (except CEPHALOPODA). 



127 



branchs the Kudistae are remarkable and characteristic. Gallery 

 The early Tertiary fossils are evidence of a gradual change VIII. 

 to present conditions, both in the character of the molluscan 

 fauna and its eventual distribution in the same provinces as 

 are at present recognised. 



V. CEPHALOPODA (Head-foot), of which the Nautilus 

 and cuttle-fish are examples. These are exhibited in 

 Gallery VII. We shall therefore leave them for the present, 

 and confine our attention to Gallery YIII., which contains 

 fossil shells of only the first four Classes, viz. : — 



AMPHINEURA, GASTROPODA, SCAPHOPODA, Gallery 

 LAMELLIBRANCHIA. WaTcases 



1—9 



It will be most convenient to start with the British Table-cases 

 specimens. Beginning at the main entrance to the Gallery, 1-16. 

 and following the numerical order of the Table-cases, these ease^^Al- 

 are arranged under the larger stratigraphical divisions, with A3 and A7. 

 the newest first. 



Post-Pliocene. The marine forms are separated from Table-cases 

 the non- marine, and are arranged under geographical districts 1 & 2. 

 in the following order : S. England, Selsea, &c. ; S.E. England, 

 including i^orfolk ; I^.E. England, chiefly Yorkshire ; W. 

 England, Gloppa, near Oswestry ; Wales, Moel Tryfaen ; 

 Ireland, the Wexford gravels and Belfast ; Scotland, Clyde 

 series; E. Scotland, chiefly Dyer's Burn and Golspie; W. 

 Scotland, including the Lewis. Some of these date from the 

 Glacial period, others are later, as indicated on the label in 

 each instance. They come from raised beaches, glacial drift, 

 and other deposits, and are often found far above present 

 sea-level, as much as 1350 feet at Moel Tryfaen, 1120 feet 

 at Gloppa, and 1200 feet at Calbeck Castle, near Dublin. 

 Some writers have supposed that they were carried to these 

 heights by moving ice. Most of the shells belong to species 

 still existing, and they are as a rule characteristic of northern 

 seas, but southern forms are sometimes associated with them. 

 In the following list of the more important species, the 

 letters IST, S, and E respectively denote the Northern, 

 Southern, and Extinct forms :— Gastropoda : Bittium reticu- 

 latum (S), Boreotrophon [Trophon] clathratum (N), Littorina 

 littorea (N), Neptunea antiqiuc (N), Tricolia [^Phasianella] 

 pulla (S), Tritonofttsus Leckenhyi (E), Turritella comm.unis 

 (N). Lamellibranchia : Acila [Nmidct] Cobholdim (E), Area 

 lactea (S), Callista [ Venus] chione (S), Cerastoderma [Cardium] 



