458 



PLIOCENE. 



The term Bryozoan or Polyzoan Crag was used by Mr. Godwin-Austen because 

 there are few Corals in this Crag, the forms which led to the proposal of the term 

 Coralline Crag being Bryozoa or Polyzoa. The terms Suffolk Crag and White 

 Crag have also been employed.^ 



The Coralline Crag has been well shown in the neighbourhood of 

 Woodbridge, Aldborough, and Orford, at Sutton (see Fig. 76), 

 Ramsholt, Tattingstone, Iken, Sudbourne, Broom Hill, Gedgrave, 

 Gomer (a small temporary excavation in a field between Low 

 Gedgrave and Broom Hill), etc. 



FxG. 76. — Section of Coralline Crag at Sutton, near Woodbridge. 

 (Prof. J. Prestwich.) 



\g: Dark ferruginous 

 beds of Polyzoa, 

 mostly in frag- 

 ments, with soft 

 white calcare- 



Polyzoan 

 zone. 



Shell zone.< 



ous veins. ii 

 feet. 



'_/". Fine sand and 

 sandstone, com- 

 minuted shells, 

 small perfect 

 shells and Poly- 

 zoa. 6 feet. 



c Fine compact 

 sand, with small 

 shells and Poly- 

 zoa in the posi- 

 tion of growth. 

 4 feet. 



Amongst the fossils are the Mollusca Cyprcea Europcea, Vohita 

 Lamherti, Turritella mcrassata, Ftisus consocialis, Trophon gracilis, 

 Scalaria dathratula, Naiica midtipunctata, Calyplrcea Chinensis, 

 Pyrula reticulata, Trochus zizyphinus, Fisstirella Grceca, Anomia 

 ephippium, Ostrea ediilis, Pecien opercidaris, P. maxivius, P. Gerardii, 

 Pinna pectinata, Pcctunculiis glycimeris, Nucula nucleus, Lncina borealis, 

 Diplodonta rotundala, Cardita senilis, C. scalaris, As t arte Omalii, A. 

 gracilis, Cyprina hlandica, C. rustica, Venus casina, Panopcea Faujasii; 

 Brachiopoda, Terehratula grandis ; Cirripedia, Balanus cnnatus ; 

 Polyzoa, Idmonca, Ritepora, Cupularia, Eschara, Fascicularia 

 aurantium, Horncra iufundibulata, Cellepora edax, C. civspitosa ; 

 Echinodermata, Echinus. Woodivardi, Temncchimis excavatus, etc. 

 Crustacea and Corals also occur. 



Altogether there are about 316 species of INIollusca, of which, 

 according to Dr. J. Gwyn Jeffreys, 52 are extinct and 264 living 

 species. Isocardia cor, which is taken to indicate a zone in the 



' T. R. Jones and W. K. Parker, Ann. Nat. Plist. (3), xiii. 65. 



