PBESTWICn CRAG-BEDS OF SUFFOLK AND NORFOLK. 



331 



Buceinum imdatum. 



Cancellaria costellifei'a. 



Calyptraea eliinensis. 



Littorina littorea. 



Natica. 



Nassa granulata. 



propinqua. 



reticosa. 



Pui'pura lapillus. 



tetragona. 



Ringicula buccinea. 

 Trophon antiquum. 



costiferum. 



gracile. 



Trochus granulatus. 



papillosus. 



Turritella incrassata. 

 Voluta Lamberti. 



Balanus crenatus. 



The following is a list of shells furnished me by the late Dr. 

 Woodward, by whom they were collected at Chillesford Stack-pit 

 in 1863. The distance between the pits is one mile ; and they are 

 both on the same level. Even in this short distance the distri- 

 bution shows a marked diiference *. Some species rare or absent 

 in the last pit are common in this one : — 



From the Cfhillesfor 



Astarte Omalii. 



Cardium angustatum (common). 



edule. 



• venustum. 



Mactra arcuata (common). 



ovalis (common). 



aubtruncata. 



Mya truncata. 



Mytihis edulis. 



Nucula Cobboldife. 



Pecten opereularis. 



Peetunculus glycymeris (common). 



Tellina crassa. 



d Stack-pit. 



Tellina obliqua (common). 



prsetenuis (common). 



Buceinum undatum. 

 Littorina littorea. 

 Natica catena. 



clausa. 



multipunctata. 



Purpura tetragona. 

 Trophon antiquum. 

 , var. contraria. 



gracile. 



Turritella incrassata. 



To these I may add — 

 Leda myalis. 



The following is also on the same 

 From a pit at 



Cardium angustatum. 



edule (frag.). 



Mactra. 



Mya arenaria. 



Pecten. 



Peetunculus glycymeris. 



Tellina prtetenuis (pair). 



Buceinum tenerum. 



Capulus ungaricus. 



Nassa reticosa. 



authority : — 

 Hollesley. 



Cerithium. 

 Nassa granulata. 



reticosa (common). 



Natica. 



Purpura lapillus. 

 Trophon antiquum. 



, var. contraria. 



gracile. 



Turritella incrassata. 



Between ChiUesford and Aldborough a range of hiUs consisting of 

 a ridge of Coralline Crag, against both flanks of which the Eed 

 Crag abuts, runs from Orford to Iken. On the eastern side of this 

 ridge there is on the whole a greater paucity of species. In one pit 



* TeUincB, so very abundant generally in the Crag, do not occur at Walton, 

 or are at all events extremely rare. 



