452 Alfred Bell — On the Butley Crag-pits. 



the number (see list) . Secondly. The Fusi, if washed out of an older 

 bed, would have suffered the loss of their apices. Thirdly. Of the 

 seven species quoted as being undoubtedly Norwich Crag forms, all 

 are common in the oldest Ked (or Middle) Crag beds, and three 

 occur in the Coralline (Lower) Crag also. 



The condition of the shells is against the presumption that they 

 have suffered from being rolled about ; they are in general very per- 

 fect, except towards the extreme right of the pit, where the greatest 

 amount of comminution obtains. 



After the Crag bed (6) had been deposited or beached up, the fine 

 sand (7) was thrown down, this passing under the Crag bed (5). In 

 this Crag bed occurs a remarkable horizontal layer, about one foot 

 thick (No. 8), of fossils, composed of land and freshwater forms in- 

 terspersed amongst others purely marine. At present it is covered 

 by the sandy talus. From this, and an overlying mass of red sand, 

 several species were procured (see list), many of which range into 

 the topmost layers of shellj matter. 



The greater part of the Molluscan fauna are of recent forms, as 

 they also are at the adjacent pits at Butley Mill, and the Chillesford 

 Stackyard. This latter pit contains Scrohicularia piperata towards 

 the top, upon which the true Chillesford sand is superimposed. This 

 shell does not occur to my knowledge at Butley, and its presence in 

 abundance implies a change in the depth and condition of the then 

 sea. 



Lastly. To compare the fauna of the Chillesford sands at Chilles- 

 ford and Sudbourn Church Walks with those of the Butley Neutral 

 Farm, and Mill Pits, the large form of Mya truncata, Lucinopsis 

 undata, Leda lanceolata (except a large fragment), and Scalaria Tur- 

 tonis, have net yet been obtained at either of the Eed Crag pits 

 mentioned ; but if the whok series of Chillesford shells are collated 

 with those of the earlier deposits, it will be found that Scalaria and 

 Lucinopsis are the only shells out of nearly 130 species, peculiar 

 to the Chillesford beds, and one Echinus {E. lividus). These cannot 

 therefore be said to have a facies peculiarly their own. 



Of the 192 species in the following list, not more than 20 are un- 

 known in a recent state, and a comparison of this with the Chilles- 

 ford fauna will best explain the reason why I consider the Butley 

 pits do not contain deposits of Chillesford age. 



Fossils from the Crag Pits at Butley, Suffolk. 



f Peculiar to the "Neutral Farm" Pit. 

 * Peculiar to the Pit near the Mill. 



The unmarked species are also found in some other Red Crag Pits. 



Pisces. Balanus crenatus. 



JRaia (not antiqua). „ Sameri. 



Lamna. „ porcatus. 



Platax Woodwardii, Eapiata.. 

 Annelida. Echinocyamus pusillus. 



Ditrupa gadus, * Toxopneustes Drobachiensis. 



Crustacea. Mollusca. 



Dancer pagurm. f Flanorbis complanatus. 



