NORWICH CRAG SERIES. 465 



is also indicated by the varieties and monstrosities of the specimens 

 of Liltorina and Purpura. The deposit is probably of the same 

 age as the upper part of the Red Crag. 



The term Fluvio-marine Crag is by no means a good name, because the higher 

 stages of the Crag are in places fluvio-marine. As Mr. Godwin-Austen remarked, 

 the fluvio-marine portions of the Crag are simply the indications of places where 

 rivers discharged into the sea. Prof. Prestwich speaks of the Norwich Crag as 

 formed in sandy bays, and mentions in support of the inflowing of streams from 

 the north and west, the occurrence in the Crag at Norwich of Lias Ammonites, 

 Carboniferous Limestone Corals, besides many fossils derived from the Chalk. 



Among the common fossils are the Mollusca, Tellina obliqua, 

 T. lata {calcarea or proxima), T. prcrJenuis, Cardium edule, Mylilus 

 edulis, Mactra ovalis, M. subtruncaia, Scrobicularia plana, Jl/ya 

 arenaria, Liltorina litlorea, Melampus {Conovulus) pyramidalis. Pur- 

 pura lapillus, Trophnn scalari/onnis, T. anliquus, Tta-rilella terebra 

 {coriummis), Cerilhium Iricinctum [punctalum), Scalaria Grcenlandica, 

 Natica calejta, N. clausa, Paludina inedia, Hydrobia subumbilicala, etc. 

 A Brachiopod, Rhynchonella psitlacea, has been occasionally met 

 with. Cirripedes, Bahums crenatus, B. porcalus, etc., are abundant. 

 Fish-remains also are plentiful ; they include Plalax Woodivardi, 

 Raia anliqua, etc. Bones of Birds have also been found, as well 

 as the Mammals previously noted. '^ Jet and Beekite are occasionally 

 met with in the Fluvio-marine Crag. 



Dr. J. E. Taylor in 1865 drew attention to the fact that at 

 Bramerton, near Norwich, where two layers of Crag are to be seen, 

 the upper division contains a larger number of shells of a northern 

 or arctic character than the lower one, which contains a larger 

 number of littoral shells ; and this Upper Crag (or ' Taylor's Bed') 

 was identified by Messrs. Wood with the Chillesford shell-bed 

 above the Red Crag at Chillesford.^ The divisions, however, are 

 of very local value, for even at Bramerton they are only separated 

 by a few feet of false-bedded sand, which contains shells sparingly ; 

 and there the so-called Chillesford Clay is a very insignificant 

 deposit. In the pit at Bramerton the following beds are seen 

 resting upon the Chalk : — 



Feet 



Bure Valley Beds. Sand and gravel 4 



/-I -n c 1 T> J ( Chillesford Clay 1 



Chillesford Beds. j chuiesford Sand with Shell-bed ... 5 



Sand with few shells 12 



Norwich 



Crag 



Series. 



Fluvio-marine Crag. \ -r-y ■ ■ n 



^ ( Pluvio-marme Crag 5 



Stone-bed i 



The Fluvio-marine Crag yields the species previously enumerated ; 

 the ' Chillesford ' shell-bed yields more abundantly ^j/ar/e' borealis, A. 

 compressa, Corbula striata, Cyprina Islandica, Leda oblongoides, Luci7ia 



^ Geol. Norwich (Geol. Survey), p. 41 ; S. Woodward, Outline of the Geology 

 of Norfolk, 1833 ; Lyell, Proc. G. S. iii. 127. 



" Taylor, G. Mag. 1871, p. 314 ; Geol. Norwich, p. 82 ; see also R. C. Taylor, 

 T. G. S. (2) i. 372, plate 47. 



