GEOLOGICAL SECTION. 139 



well seen. It forms the top of the quarry, and is ahout eight 

 feet thick. Fossils are found chiefly at the base, in a layer lying 

 on \ he Forest Marble and intimately joined to it. The roots of 

 Apwcrinus are here " in situ" as they grew ; the columns are 

 mostly broken up, and perfect heads even are rare, though parts 

 and detached plates are very abundant. The other chief fossils 

 were Aricula costata, Terehratula digona and eoarctata, all 

 extrc mely characteristic and abundant. Below the *' Forest 

 Marble" with its fragments of plant-remains and Strophodus 

 teeth, are the thicker beds of the Bath Oolite, quarried for 

 build ing stone. The bedding of the top beds is horizontal, but 

 at the base throughout the quarry it is oblique, though the courses 

 remain of the same average thickness; these diagonal joints, being 

 all in the same direction, produce a false appearance of 

 unconformability. Unless the circumstances are taken into 

 account, it would lead to over-estimation of the thickness of the 

 deposit. It is apparently due to the matter having been deposited 

 by currents, and not an unusual feature in the Bath Oolite (see 

 Proce Klings of Bath N.H. Club, II. p. 246.) Not many fossils were 

 found in the lower beds ; Eunomia radiata and several small 

 univalves, however, were obtained. 



The second walk was on June 3rd (Whit Tuesday.) Members 

 left Bristol by the 8.45 train for Woodchester, and walked thence 

 to the Minchinhampton quarries, which are on the top of a high 

 Down. 



Th(; ''planking beds" of the Great Oolite form the top of the 

 quarry. It is from these chiefly that such a rich fauna has been 

 obtained, but the party were not fortunate in any of the quarries. 

 After exploring pretty well the whole Common, they turned in to 

 the Anibf-rley Inn for tea, and thence to the station, after a short 

 excursion up one of the opposite slopes. 



The third walk was on September 12th. By train to Berkeley 

 Road Station, thence on foot to Stinchcombe quarries, where a 

 fine section of M. Lias, or Marlstone is exposed. Fossils numerous. 

 Ammonites spinatus was found in the same layer with Rhynchonella 



