Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/613

 This pit shows also the relation of the Crag-beds to the overlying series. I give the section (fig. 28) I took in 1856, as at that time a thin seam of clay, which is probably the equivalent of the Chillesford Clay, and a layer of pebbly iron-sandstone, with casts and impressions of shells, were well exposed at the east end of the pit *. On that occasion also I found a fragment of Deer's horn immediately upon the Chillesford Clay in the ferruginous gravel.

Mr. R. Taylor, so early as 1826, showed in his section of Bramerton pit that the fossils were grouped differently in the several beds, and that some of the shells were peculiar to certain beds. Mr. J. E. Taylor has recently† shown the differences to be still more marked. He found that the upper beds of the Norwich pits were characterized more especially by the much greater abundance of deeper-water and more northern shells, and the lower beds by a more littoral and freshwater group. Mr. Taylor and Mr. S. Wood, jun., refer this upper division to the zone of the Chillesford series. This, as they justly notice, is an important elimination, as it places the lower division of the Norwich Crag on terms which admit of a juster comparison with the Red Crag of Suffolk, to which they refer the lower beds. On general grounds I had long held these two crags to be synchronous; but the correlation of the molluscan fauna still presented some difficulties, which this determination of Mr. Taylor may help to remove. Owing to the absence of sections in Mr. Taylor's paper, I am uncertain how far I agree with him in correlating these divisions at Bramerton with others at a distance from Norwich and on the coast. The Chillesford Clay is not visible in the Bramerton pit ; but I have found traces of it in the road leading up the hill at the back of the pit.

I am indebted to Mr. James Reeve, Curator of the Norwich Museum, for the following carefully worked out list of the shells from Bramerton, showing, I believe, more completely than has hitherto been done, the species proper to the upper and lower divisions. For a further list, comprising all the species recorded from the Norfolk Crag, I beg to refer to the general list at the end of this paper, where, in column VI. the different localities at which the several species have been found are given : —

List of Shells in the Norwich Museum from the Sand-pit on the Common at Bramerton, collected by Mr. Reeve.

Univalves. Upper Lower

Beds. Beds.

Admete viridula ..... 1

Buccinum undatum c c

Bulla obtusa v r r

Calyptraea chinensis ..... r

Cerithium tricinctum c c

Chemnitzia internodula ..... vr

Univalves. Upper Lower

Beds. Beds.

Clavatula turricula v r r

Conovulus pyramydalis ..... r

Hydrobia ulvae ..... v r

Lacuna crassior ? ..... 1

Littorina littorea c v c

— rudis n c n c

exposed at the west end of the pit. The clay there varies from 1 to 2 feet in thickness, and the iron sandstone is about 1 foot thick. The former contains some large subangular flints, but no shells ; the latter is full of well-preserved shells (see Geol. Mag. vol. vii. p. 539.)
 * On visiting this pit again last summer (1870) I found the same beds still better

† Geol. Mag. vol. iii. p. 273, vol. iv. p. 331.