514 MESSES. WHITE AND TREACHER ON THE [Aug. I906, 



general surface of the field. It is to be inferred that this belem- 

 noid-bearing rubble marks the outcrop of Chalk contemporaneous 

 (if not continuous) with that forming bed (4) and the lower part 

 of bed (5) of the Winterbourne (a) section, three-quarters of a mile 

 to the east. We found remains of Marsupites and of Uintacrinus, 

 in their proper relative positions, farther down the slope towards 

 Hangman-stone Lane. 



Followed southward, the upper limit of the rubble-belt diverges 

 markedly from the Eocene boundary, and falls nearly to the 

 400-foot contour on the end of the blunt spur to the south-west 

 of Borough-Hill Camp, leaving room for about 15 feet of higher 

 Chalk between the rock-band which it indicates and the base of the 

 Reading Beds. Near this spot, there seems to be a considerable 

 development of hard beds in the Chalk, for a closely-packed rubble 

 of the yellow, sponge-impressed rock, almost bare of soil, extends 

 down the side of the valley (of Hangman-stone Lane) for a vertical 

 distance of 40 or 50 feet, and is marked by a faint terrace-feature 

 near its lower limit. 



Between the end of the spur before mentioned and the head of 

 the re-entrant by Borough Copse, the bed yielding the hard rubble 

 either becomes greatly reduced in thickness, or is more thickly 

 covered by wash from the Reading Beds, as it ceases to be con- 

 tinuously traceable. There are only two fair exposures of the 

 Actinocamax-quadratus Chalk above it— those marked (k) and (1). 



The first of these (k) is in a small overgrown pit, at the end of a 

 cart-track. The southern side of the working shows a few square 

 feet of soft, white, fTintless chalk traversed by fine, straight, tubular 

 borings filled with material of a coarse texture, in which fish-remains 

 and brown grains are apparent. The wash-residues consist of 

 unphosphatized tests of Rotaliidae (to 0*7 mm. in diameter); plates 

 and subangular lumps of calcite (commonly 0*2 to 0*5 mm.) ; prisms 

 of Inoceramus ; chips of fish-teeth, bones, and scales ; a few brown 

 coprolites and phospbatized casts of Globigerina and Tecctularia ; 

 some black granules and rare quartz-grains (to 0'25 millimetre). 



The bigger fossils noticed in this slightly-phosphatized Chalk 



Inoceramus sp. 

 Ostrea sp. 



Rhynclionella plicatilis, Sen 

 Serpula plana, S. Woodw. 



Asteroid-ossicles. 

 Torosphcera globular is (Phill.). 

 Porosphcera pileolus, Lam. 



Part of what seems to be a detached body, or lenticle, of very 

 hard j-ellowish chalk is exposed on the north side of the pit. 



Exposure (1) is in a patch of soft rubble a little above the 

 400-foot contour, and close upon the boundary of the Reading 

 Beds. The solid rock, forming a remarkably-even floor to the 

 soil, and lying less than a foot below the surface, is coarse and 

 gritty, and has the characteristic grey hue of Phosphatic Chalk. 

 Its residues, which have a pink or flesh-coloured tint, resemble 



