PRESTWICH CRAG -BEDS OF SUFFOLK AND NORFOLK. 



119 



Coralline Crag. It is on the side of this old yard, and therefore im- 

 mediately above the bed with Oardita &c.,that the Coralline Crag rises 

 in an old clilEF well described by Sir Charles Lyell *, and to which I 

 shall have occasion to refer again. The lower part of this cliff con- 

 sists of light-coloured sands (e), with a few Bryozoa and a good many 

 small shells ; while the upper part (part of/) is composed in great part 

 of comminuted shells. No higher bed is seen here ; but on the other 

 side of the hill, and at a distance of 400 feet west of this pit, is an old 

 quarry, which, when I first visited it in 1836, had recently been ex- 

 tensively worked for rubble to form the river-wall. In the lower part 

 of this pit (fig. 2) the bed of sand e, just referred to in the Bullock- 

 Fig. 2. — Section in old Quarry, Sutton. Top of hill overlooMng the 

 Dehen. (See f, Map and Sections, PL VI.) 



Surface soil. 



3 Dark ferruginous beds of Bryozoa, mostly 

 in fragments, some entire, with a few 

 shells in the same state. White soft 

 calcareous veins descend through these 



^ beds from the top. 11 feet. 



Y'.'.-ii^,^^^^^ I / Pine sand and grit, comminuted shells, 

 numerous small perfect shells, and 

 some Bryozoa. 6 feet. 



/'"' ;;;^':\;:;TrvrT:; :;:;;;, "I C Uniform fine compact sand, with small 



■':-:y;k^:;-.>:'-.5 S. shells and Bryozoa in the position of 



; i/.": V-.'si-Vv-;.- ( growth. 4 feet. 



yard pit, is weU exposed. It is 12 feet thick, and consists of a light 

 yellow sand, with a few shells, mostly smaU or young individuals, with 

 a number of Bryozoa in a fine state of preservation and mostly in the 

 position in which they lived. In some places these Bryozoa are very 

 numerous, and arranged in regular but not continuous bands, like 

 flints in the Chalk. The prevailing species are Cellepora corono'porus, 

 Eschara porosa, and other species of Cellepora and Escliara, a species of 

 Ceriopora, and another large branching species. Many of these are m 

 the most beautiful state of preservation and perfectly uninjured. They 

 are now, however, best seen in a small section between the large pit 

 or quarry and the cottages at the entrance to the Bullock-yard. 



Overlying these sands with undisturbed Bryozoa is a bed, /, from 

 5 to 8 feet thick, consisting of comminuted shells with seams of 

 oblique lamination, containing a few Bryozoa, and with a consider- 

 able number of shells, also mostly small or young individuals, in a 

 good state of preservation. Intercalated in this bed are several 

 finely laminated indurated irregular seams of yellow marl or lime- 

 stone, containing small shells. Foraminifera, and some rare species 



0^7. Cif. 



