PRESTWICH — CRAG-BEDS OF SUFFOLK AND NOEFOLK. 



117 



a basement bed with fossils and boulders of an unexpected and 

 remarkable character (fig. 1). 



Fig. 1. — Section of old pit on Mr. Colchester's farm, Sutton. 



Surface soil. 

 d. White marly sands with seams of Cyprlna. 



c. Ditto with Mf/a and Bryozoa in lower part, 



J /~i.,.j:j.^ A^J-r.nx^/i Avirfi^iin artCi T^fin)!.^) 



and Curdita, Astarte, Anomia, and Venus 

 common in upper part. 



6. Bed of comminuted shells, with single valves 

 of Cyprlna, Pecteiu Cellepora cmspiiosa, &c. 



^ a Bed of phosphatic nodules, with mammalian 

 and cetacean remains, and foreign boulders. 

 London Clay. 



(Unless mentioned to the contrary, all the pit-sections in this paper are on 

 the same scale, viz. 12 feet to the inch vertical.) 



The surface of the London Clay is here 8 feet above high-water 

 level of the adjacent river Deben. Immediately on the London Clay 

 we find a bed, from 1 to 1| foot thick, of phosphatic nodules, not to 

 be distinguished in general appearance from those of the Eed Crag. 

 Among them I found, as in the Bed Crag, a great many fossil 

 Crustacea, much worn, derived from the London Clay, and consisting 

 of the following species : — 



Scyllaridia Kcenigii. 

 Thenops scyllariformis. 

 Xanthopsis Leachii. 

 Xantholithes Bowerbankii. 



Archffiocarabus Bowerbankii. 



Dromolites Bucklandii. 



Hoploparia Bellii. 



gammaroides. 



With these I found one fragment of the horn of a Deer much mine- 

 ralized, a smaU Cetacean vertebra retaining the ordinary bone- 

 structure, together with numerous teeth of sharks. In the same bed 

 were worn blocks of Septaria from the London Clay, driUed by boring 

 moUusca, and flat, worn, highly mineraHzed Cetacean bones, super- 

 ficially punctured, as those in the Eed Crag, together with frag-ments 

 of Bryozoa, Terehratula grandis, and Ciiprina, much worn, and the 

 latter full of the cavities made by minute boring sponges. With these 

 organic remains there were a small number of the nodules or balls 

 of coarse dark-brown sandstone, often containing the cast of a shell, 

 so common in places in the Red Crag ; there were also small pebbles 

 of quartz and of flints, and some large pebbles of light-coloured, 

 hard, siliceous sandstone : but the most remarkable specimen I there 

 found was a rounded boulder of dark-red porphyry of considerable 

 size, and weighing about a quarter of a ton. None of the specimens 

 were angular or striated. 



On mentioning these circumstances to Mr. Colchester, I found 



