FOREST MARBLE : BRADFORD CLAY. 853 
to be seen any openings that show the Bradford Clay in the 
escarpment north of Winsley.* 
The thickness of the Bradford Clay does not exceed 10 feet at 
Bradford-on-Avon, but it has been estimated to be thicker near 
Farleigh, where however other portions of the Forest Marble 
have been doubtless included. 
It seems evident that locally there was some pause in deposition 
between the Great Oolite and the Bradford Clay, for the Crinoida 
or " stone-lilies " must have flourished in clear water on the floor 
of Great Oolite, before the muddy sediments of the Bradford Clay 
were laid down. Moreover it has been noticed that some of the 
Crinoids have been covered with Serpulae, and afterwards 
encrusted with Polyzoa.f 
In other localities, when we get no distinctive evidence of 
Bradford Clay, there was probably no pause in deposition, no 
growth of Crinoids, and no accumulation of organic remains to 
form a fossil-bed. The Great Oolite and Forest Marble are 
then more or less interblended, and it is hard to say where the 
stratigraphical division should be made. 
The fossils of the Bradford Clay include the following 
species : 
Area minuta. 
Avicula costata, 
Corbicella subangulata. 
Cypriua islipensis. 
Lima duplicate. 
Modiola furcata. 
imbricata. 
Nucula Waltoni. 
Ostrea gregaria. 
lingulata. 
Sowerbyi. 
Pecten vagans. 
Rhynchonella concinna. 
obaoleta. 
varians. 
Terebratula coarctata. 
maxillata. 
Waldheimia cardium. 
digona. 
Apiocrinus Parkinsoni. 
Acrosalenia spinosa. 
Cidaris bradfordensis. 
Serpula grandis. 
Terebellaria ramosissima. 
A very fine collection of fossils from the Bradford Clay was 
made by J. Chaning Pearce, who residing for a time at Bradford- 
on-Avon, obtained splendid specimens of the " Bradford Encrinite," 
when the clay was removed from the surface of the stone during 
the working of the quarries.^ Mr. William Cunnington also 
obtained many specimens. Some Foraminifera and Ostracoda 
have been procured from the marly clay above the fossil-bed. || 
The best section I saw of the Bradford Clay, was shown to the 
south of Bradford-on-Avon, in a quarry north of the lane leading 
to Upper Westwood : it was as follows (see Fig. 1 00) : 
* See William Smith, Strata Identified ; and Lonsdale, Trans. Geol. Soc., ser. 2, 
vol. iii. p. 255. 
t Witchell, Geol. Stroud, p. 82. 
j See Proc. Geol. Assoc., rol. ix. p. 165 ; vol. xiii. p. 182. The Pearce Collection 
is now in the possession of Dr. J. C. Pearce at Eanwgate. 
Mag. Wilts Nat. Hist. Soc., rol. vi. p. 10. 
|| T. R. Jones and C. D. Sherboro, Geol. Mag. 1886, p. 273. 
E 75928. z 
