Yol. 57.] UPPER GREENSAND AND CHLORITIC MARL OF WILTSHIRE. 107 



It is a hard, greyish, siliceous cherty stone, full of 

 sponge-spicules, but ouly 6 inches thick. 



Bed E is a greenish-grey glauconitic sand, consisting 

 largely of even-sized grains of quartz with many of glauconite, some 

 of which are light green. At its base occur occasional lenticular 

 layers of white floury silt, similar to the material in No. 8 of the 

 Maiden-Bradley section, and in these many sponges are to be 

 found : among them species of Ohenendopora, Doryderma, Nema- 

 tinion, Pachypoterion, and Siplionia have been identified for us by 

 Dr. G. J. Hinde, P.H.S. 



Bed F consists of two parts : (1) an upper course made up of large 

 blocksof compact glauconitic sandstone in lenticular masses, 

 but forming a nearly continuous course about 2 feet thick ; and 

 (2) a lower layer of yellowish sand which in places is concreted 

 into granular spiculif erous sandstone. This band is note- 

 worthy as having yielded several species of Crustacea, and is probably 

 the bed from which Baker, the fossil-collector of Warminster, ob- 

 tained most of his crabs. The upper part has yielded Necrocarcinus 

 iricarinatus and N. glaher, the latter being the new species de- 

 scribed by Dr. Henry Woodward in 1898 ^ : the lower part contains 

 N. glaber and J^. Becliei. Fecten asjoer, P. orbicularis, Neithea 

 cequicostata, Lima semiornata, L. semisidcata, Ostrea vesicularis, and 

 0. vesiculosa have been found in these two beds, which seem to 

 represent the lowest horizons exposed at Maiden Bradley. 



BedGisa calcareous sandstone, consisting of quartz-grains, 

 fragments of the large spicules of Lithistid sponges, and glauconite- 

 grains, all cemented more or less firmly by crystalline calcite into a 

 rock which is harder than any of the overlying beds. The only 

 fossils obtained from it are Lima semisulcata and Neithea cec^uicostata. 



Bed H is a compact grey glauconitic sand, effervescing 

 freely with acid, so that it must contain much calcareous matter. 

 When a portion is washed and placed under the microscope, it is seen 

 to consist largely of small well-rounded grains of quartz-sand; grains 

 of dark green glauconite are also abundant, with a few which are 

 greenish-yellow ; and there are many dull white bodies which seem 

 to be foraminifera. Plakes of silvery mica also occur. This sand, 

 as seen in the quarry, encloses many large irregular lumps or blocks 

 of cherty stone, some of which weigh from 2 to 3 cwt. Most of 

 these have centres of brown or black chalcedonic chert, and it is 

 these cherts that make the best road-metal. 



Broken pieces of Pecten asper are common in this bed, but the 

 only other fossil found is a Serpula. 



Bed I is a greyish-white marly silt, very like Beds A & C, 

 1 Geol. Mag. 1898, p. 302. 



