232 PEOF. S. H. REYNOLDS ON THE LITHOLOaiCAL [vol. IxxVli, 



The Concretionaiy Beds are also well exposed b}' the roadside 

 from the bio- rock-face south of the Bridsje to their termination at 

 a point just north of the Old Zigzag- path. Immediately" aboA'e 

 the highest concretionary bed is a band of pisolite, and on this 

 rests a band with Alveolites septosa ; this band is about 40 feet 

 below the base of D^. 



Exposures of the Seminula Beds on the left bank. 



The main section : S^.^ — On the Leigh Woods side nothing 

 is seen of the lower part of S^, the lowest bed met with being 

 the Caninia-hnstolensis Bed, which is exposed in the irregular 

 dip-slope forming the northern boundary of Quarr}^ 4. This 

 fossil, associated with Litliostrotion, occurs somewhat abundantly 

 on the bedding-planes, which are often determined by red shaly 

 partings. The overlying rocks (top of SJ are fairl}' well seen 

 in the western wall of the quarry. 



S^. — The base of S^ (^Seminula Pisolite, etc. ; S., «) is very 

 poorly exposed, the rocks being much veined by calcite.i The 

 upper pisolites and overlying chert and dolomite are well exposed. 

 The cherts, below which, as in the Great Quarry on the right bank, 

 masses of DiphypliyUum are met with, can be followed along the 

 southern face of Quarry 4 to the exposure in the railway-cutting. 



The Seminula Oolite, S.^ (h), which forms the upper part of the 

 western and southern walls of Quarry 4, is in a very bad state for 

 examination, the exposed surfaces being chiefly weathered joint- 

 faces. The northern part of the cutting between Quarries 4 & 5 

 is in the Seminula Oolite, which is well seen. In the southern 

 part of the cutting and in Quarry 5 the variable limestones, S^ (c), 

 which separate the Seminula Oolite from the Concretionary Beds 

 are well exposed. They are chiefly massive limestones with 

 Litliostrotion- and C]ionetes-\)2iY\di^, but include also china-stones, 

 dolomites, and oolites. The Concretionary Beds, S,^ (fZ), come on 

 at the top of Quarry 5, and their base is seen in the exposure by 

 the roadside at the tunnel-entrance, the concretionary layers being 

 associated with banded china-stone. The tunnel-slope south of 

 Quarry 5 is formed of Concretionary Beds. A splendid riverside 

 section of pai-t of S^ and D^ begins opposite the entrance to that 

 quarry. The lowest beds belong to the Seminula-OoMte series, 

 S, (5), and consist mainlj^of massive oolite with some foraminiferal 

 limestone, also Seminula- and Procliictus-hRnds. The overlying 

 variable limestones, S., (c), are better seen than in Quarry 5, and 

 the china-stones include rocks which are white on the weathered 

 surface, but black when freshly broken (like those from S, in the 

 Grreat Quarry). Brecciated and pisolitic bands also occur: in fact, 

 there is a development in the upper beds of all the lagoon-phase 

 rock-t^^pes. The Concretionary Beds, S^ (d), which in the quarry- 



^ The red flaggy and shaly material associated with these beds in Quarry 4 

 is probably due to a Triassic infilling. 



