262 A. J. Jukes-Brou-ne— 



It was evident, therefore, that wlien this pit was worked it exposed 

 a soft fossiliferous greensand overlain by sandy " Chloritic Marl," 

 which is also generally a bed rich in fossils ; consequently it is 

 highly probable that the collections made by Baker included all the 

 fossils he could get from both horizons, and from the surface of the 

 surrounding field. 



At Eye Hill Farm (Ray Hill on the old Ordnance Map), half 

 a mile south-east of Shute Farm, there are some small pits still open, 

 which show the junction of Chalk and Greensand very clearly, 

 a light-green fossiliferous sand passing up into greenish sandy marl 

 with a few scattered phosphatic nodules, and further up the lane 

 harder " Chloritic Marl" with more phosphates can be found. The 

 chert beds crop out in the lane to the eastward, and the total 

 thickness of the soft greensand cannot be more than ten feet. 



The fossils in this sand are chiefly the small Echinoderms and 

 Brachiopods, which are such well known " Warminster fossils." 

 Small lumps of pale-yellow calcareous material also occur in the 

 sand, and some of these are casts of Ammonites varians and Am. 

 curvatus, which do not occur in any other state of preservation, and 

 are easily distinguished from the casts in brown phosphate which 

 are so common in the overlying Chloritic Marl. 



This sand and the Chloritic Marl are not, however, the only 

 sources whence Baker may have got his fossils. He had no 

 knowledge of geology, and would naturally mix together all fossils 

 which he obtained from greensands and sandstones near Warminster. 

 The chert beds, which consist of greenish-grey sands with lenticular 

 layers of chert and cherty stone, are dug for road-metal at Long- 

 bridge Deverill, Sutton Veny, Boreham, and Warminster. These 

 beds yield siliceous sponges, some large Echinoderms, Neithea 

 quadricostata, Pecten asper, and P. orbicularis. Still lower are 

 coarse glauconitic sands with a layer of greenish calcareous sand- 

 stone, which is the home of four species of Pecten — P. asper, 

 P. orbicularis, P. Galliennei, and P. (Janira) quadricostata. These 

 beds are well exposed at Longbridge Deverill, and were doubtless 

 laid under contribution by Baker in making up his collections, for 

 I have detected specimens with this matrix in several museums. 



The several beds of greensand above mentioned exhibit differences 

 which enable one who is familiar with them to distinguish land 

 specimens from one another, and the fossils of each can also be 

 separated when sufficient matrix is attached. 



Thus the matrix of the chert beds is a pale whitish-grey silty 

 sand, fine-grained and powdery, with very small grains of glauconite; 

 it is often cemented by silica into a hard siliceous stone. The stone- 

 bed below is a rather coarse sandstone, decidedly green from the 

 abundance of glauconite, and cemented by calcite. 



The Rye Hill Sand is also rather coarse, with large grains of quartz 

 but with less glauconite, so that in colour it is pale greenish-grey. 

 The sand grains often cling closely to the fossils, and appear to be 

 glued to them by a thin coating of silica. 



JSone of these sands contain mica, so that any fossils imbedded in 



