GENERAL ACCOUNT OF THE DEPOSITS. 5 



coral rag mixed up with the clayey material of the Kimmeridge 

 Clay in such a manner that it "actually presents the appearance of 

 Boulder Drift." This deposit is of limited extent, in the line of 

 junction at the base of the Lower Greensand only. 



(C) Then we come to the first definite bed of the Up ware 

 Neocomian — bed C. 1, of section — a pebbly sand and rocky con- 

 glomerate bed about one foot thick. The pebbles are mostly 

 phosphate of lime, together with chert and Lydian stones, vein 

 quartz, quartzite, jasper (less common) and coral rag (still rarer). 

 The quartzites are of very various grain and colour, clear to opaque 

 white, pink, yellow, and sometimes very dark; fragments of iron- 

 stone and iron sandstone are abundant, and some fine grained pink 

 sandstones are occasionally found. All these rocks are very frag- 

 mentary and are more or less worn, some being quite rounded into 

 pebbles, but the majority by far are still angular or subangular in 

 their contours. These different stones, varying in size, mostly 

 between the measurements of peas, beans, and walnuts are mingled 

 together without order in a matrix of sand, with occasional oolitic 

 grains of coral rag origin. Here and there these materials are 

 cemented together by carbonate of lime to form irregular patches 

 and nodules of conglomerate, in which many fossils were found. 

 Each pebble in the hard conglomerate is enveloped in a filmy 

 case of carbonate of lime which has formed around it in the matrix. 



Mixed up with these pebbles are the shells of Mollusca, which, 

 strange to say, are not at all worn but excellently well preserved, 

 although some of them are of a very delicate nature ; and from this 

 bed many of the best fossils were obtained, especially the indi- 

 genous Lamellibranchs and Gasteropoda. The richness of ' this 

 bed in fossils, its hard conglomeratic character, and the excellent 

 preservation of its shells are probably all connected with its con- 

 tiguity with the coral rag. 



(C. 2) Above the 'lower phosphate bed' just described comes 

 a bed of loose sand, or 'silt,' red and yellow coloured, and composed 

 for the most part of grains of quartz, Lydian stone, chert, and iron- 

 stone. Some of the quartz grains are blue and amethystine. 

 Near the junction lines some irregular masses and nodules of 

 irony and slightly phosphatic sand rock are found, which we again 

 refer to in the sequel. 



(C. 3) Next we come to the upper nodule bed which differs 



