358 A. J. Julies Browne — On the Upper Greensand, etc. 
Chloritic Marl, it is evident tbat this identification is not correct, and 
that these beds must be restored to the Upper Greensand. 1 
The mi stäke was probably caused by the existence of remanies 
fossils from the Warminster beds in the Chloritic Marl of the Isle 
of Wight, imparting to its fauna the semblance of that below ; this 
appears to be also the case with its probable equivalent in the Devon- 
shire section, namely, that numbered 13 by Mr. Meyer, whick he 
describes as resting upon an uneven surface of the bed below, and 
as containing numerous pkosphate nodules and casts of skells, some 
of whick he regards as having probably been derived from the erosion 
of the beds below. He rightly considers this bed as forming the 
base of the Chalk Marl, and remarks upon the importance of the 
line formed by its marked Separation from the Warminster beds. 
The paper indeed is a valuable one, for though mistaken in one 
particular, be correctly States the infra-position of the Blackdown to 
the Warminster beds, and of the latter to whatis really theGhloritic 
Marl ; the true relations of these beds had not before been ascer- 
tained, and the lists of fossils afford the means of determining and 
recognizing the beds over a larger area. 
I have previously drawn attention to the similarity between the 
conditions presented by the base of the Chalk Marl in Devonshire 
and those observable in the Cambridge Greensand; 2 there can, I 
think, be little doubt that the two beds occupy exactly the same 
horizon, and that the fossil contents of both are to a greater or 
less extent remanies. There is, however, this great difference be- 
tween the two sets of derived fossils, viz. that the one of tkem 
was derived from the fauna of the Warminster beds, and the otker 
from that of the Upper Gault ; the reasons of this difference I have 
also fully explained. 3 The Cambridge bed has been described as 
Chloritic Marl by the Rev. T. G. Bonney in a paper read before 
the Geologists’ Association in 1872, 4 and more recently in bis Cam- 
bridgeshire Geology, but witkont distinctly comparing it to the 
Chloritic Marl of the Isle of Wight ; in the formier paper, indeed, 
he was inclined to regard it as to some extent the equivalent of 
the Upper Greensand, but adds at p. 19, “ It must, however, be 
remembered that, probably, our Cambridge bed is ratker homo- 
taxial than absolutely contemporaneous with some at least of the 
more Western developments of the South of England -Upper Green- 
sands.” I think, however, I am not misrepresenting Mr. Bonney’s 
present views in saying that he concurs with me in considering the 
Nodule Bed as forming the actual base of the Chalk Marl, and, 
tkerefore, as the exact equivalent of the Chloritic Marl according 
to its more recent definition. 
1 See Barrois, Sur l’age des couches de Blackdown, Ann. Soc. Geol. du Nord, 
tom. iii. p. 7. 
2 Quart. Journ. Geol. Soc., vol. xxxi. p. 272. 
3 The fact of the entire absence of the characteristic fossils of the "Warminster beds 
in the Cambridge Greensand is suflicient proof that these beds were never deposited 
in that area, loc. cit., pp. 272, 273. 
4 Proc. Geol. Assoc., vol. iii. 
