72 LIAS OF ENGLAND AND WALES: 
interfering with the sequence of the species. Inland we have to 
depend on comparatively limited sections, sometimes revealing 
evidence of a single zone, in other cases of a blending of two 
zone?. It must be remembered however that to obtain good 
specimens in situ is often a difficult task : the best examples, 
whether from brickyards or quarries, being most frequently 
obtained from workmen or from the spoil-heaps, so that the 
precise position of each fossil cannot always be determined. 
Inland sections, Dorsetshire and Devonshire to Membury and 
Chard. 
Proceeding inland from the Dorsetshire coast, the Lower Lias 
limestones may be traced at U ply me and Axminster, and thence 
by Membury to the higher part of the Yart Valley near Buckland 
St. Mary ; but their outcrop is much obscured by the overstepping 
of the Upper Greensand and Chalk, which form the dominant 
features in this area. 
The quarries at Uplyme are situated a short distance north-west 
of the church ; and in the one known as Fowler's quarry, about 
25 feet of Lower Lias limestone and clay may be seen resting on 
the White Lias. 
In this neighbourhood, also near Axminster, and again near 
Street in Somersetshire, there is sometimes a difficulty in readily 
determining the junction between the Lower Lias and White 
Lias. Among the Lower Lias limestones there are beds of 
pale marly limestone and compact limestone that much resemble 
beds of White Lias, and locally the term " White Lias " is applied 
by the quarrymen to them, while the name ce White Rock " is given 
to the true White Lias. To this fact we may attribute 
Dr. Wright's grouping of the White Lias in the zone of Ammo- 
nites planorbis, a grouping that was strongly opposed by Charles 
Moore,*" and has been shown by subsequent observations to have 
been based on a mistaken identification of the beds. 
It will be noticed however at Uplyme, as well as at Pinhay Bay, 
that the White Lias, which yields Modiola minima, Ostrea liassica, 
Cardium rhceticum, and Pecten valoniensis, contains here and there 
throughout its mass, nodules or pebbles of compact limestone, that 
stand out conspicuously on the weathered surfaces. These 
included portions of limestone are sometimes more compact than 
the matrix, but in no case do they differ from beds represented in 
the White Lias. They appear to be due to some contemporaneous 
destruction of the beds, and when I accompanied Sir A. Geikieto 
the Dorsetshire coast in 1885, he suggested that the calcareous 
mud may, during the accumulation of the strata, have been from 
time to time exposed to Ihe sun's rays, so that films of mud might 
have curled up, and thes?, if subsequently rolled by an incoming 
tide, would be shaped into the lumps which form so conspicuous 
* Quart. Journ. Geol. Soc., vol. xvii. p. 483 ; Wright, Ibid., vol. xvi. p. 396 ; and 
Lias Ammonites (Pal. Soc.), p. 21 ; also H. B. W., Proc. Geol. Assoc., vol. xi. 
p. xxx. 
