RED AJSD NORWICH CRAGS. 
103 
sections occur at Sizewell, but the base of the Crag has not been 
reached, though sunk rocks of Coralline Crag are found about a 
mile from the shore. Prof. Prestwich records 20 species of 
mollusca from a well at Sizewell, and notes the occurrence with 
them of fragments of Coralline Crag—probably showing that the 
upper sands overlapped the older Red Crag, and abutted against 
the ridge of Coralline Crag, The Chillesford Clay is cut out by 
later deposits in this neighbourhood, and the immediately under¬ 
lying Chillesford Crag has not been recognised. 
Continuing northward along the coast, there is now a gap of 
over two miles, occupied by the Alluvium of the Minsmere Level. 
Immediately north of this, where the cliff recommences, near 
Dunwich, Norwich Crag has been discovered by Messrs. Crowfoot 
and Dowson, who give a list of 44 species of mollusca, obtained 
principally from an exposure between tide-marks. Mammalian 
remains were also found, and these appeared to come from a 
hard ferruginous bed of clay and sand, shown here and there on 
the beach, some feet below the shell-bed in thecliff.”'^ As this is 
the most southerly locality from which a large and typical Norwich 
Crag fauna has been obtained, Messrs. Crowfoot and Dowson’s 
list is here quoted. The arctic and also the estuarine character 
of the fauna is very marked. 
Fossils from the Crag at Dunwich, 
(Identified in all doubtful cases by S. Y. Wood.) 
c. Common. r. Rare. 
V. c. Very common. v. r. Very rare, 
a. Abundant. 
Astarte compressa - 
- r. 
Cerithium tricinotum - v. c. 
- sulcata 
- v. r. 
Helix bispida 
“ v. r. 
Cardita (derived ?) 
=■ v. r. 
Hydrobia ulvae 
- c. 
Cardium edule 
- a. 
Littorina littorea 
- a. 
- groenlandicum 
» V. c. 
- rudis 
- r. 
Corbicula fluminalis - 
- c. 
Melampus pyramidalis - c. 
Corbula striata 
- V. c. 
Natica catena P 
- - c. 
Oyprina islandica 
" a. 
- clausa 
- - r. 
Leda oblongoides 
- r. 
-— helicoides 
- r. 
Loripes divaricatus - 
- V. r. 
Paludina media 
- c. 
Lucina borealis 
- V. a. 
Purpura lapillus 
- a. 
Mactra arcuata 
- V. r. 
Ringicula ventricosa p - r. 
- stultorum 
- r. 
Scalaria sp. - 
- v, r. 
- subtruncata - 
- V. c. 
Trophon antiquus 
- - To 
4-r*tirk-I* 
TTQT* 
9 
Vd;l* 
Mya arenaria 
- a. 
traria 
- V. r. 
Mytilus edulis 
- c. 
- gracilis P 
- V. r. 
Nucula Cobboldisc - 
- c. 
Turritella terebra 
- r. 
Pecten opercularis - 
- c. 
Scrobicularia plana - 
- V. c. 
Pish bones. 
Solen siliqua - 
- a. 
Arvicola (teeth). 
Tapes virgineus 
- v. c. 
Bos. 
Tellina lata - 
- a. 
Cetacea. 
- obliqua 
- a. 
Cervus. 
- prsctenuis 
- a. 
Elephas. 
Equus. 
Calyptraaa chinensis - 
- V. r. 
Rhinoceros. 
Cancellaria viridula P 
- V. r. 
North and west of D unwich there is an area of a good many 
square miles occupied by pebbly gravel, and by sands without 
^ Vroc, Norwich Geol, Soc., vol. i. part HI, pp. 80-83. (181^9.) 
