BRITISH ASSOCIATION MEETING AT CAMBRIDGE. 
421 
gical phenomena he had noticed in the Carboniferous Limestones of tlie 
Mendip ITiJIs. Through the whole of this district he observed that the 
beds had been very much fissured, and that most of them had subsequently- 
been filled in with deposits containing numerous organic remains of dif- 
ferent geological ages, some of which were probably as young as the Infe- 
rior Oolite. A small roadside section at Holwell, on the south-east of 
the Mendip, was described, in which, at the base, Carboniferous Lime- 
stone was present ; whilst resting unconformably upon it was a dense un- 
stratified conglomeratic deposit, contaiaing shells of the age of the Middle 
Lias, and on tliis rested thin horizontal beds of Inferior Oolite. The out- 
crop of a mineral vein was also present in this section. IS'ear the above 
was a quarry 200 feet in length, witjiin which were thirteen vertical fis- 
sures passing down through inclined stratified beds of Carboniferous Lime- 
stone : one of them being fifteen feet in breadth at the base of the quarry. 
These fissures, which occupied nearly one-third of the section, had been 
filled in by a dense variegated limestone, containing occasionally Brachio- 
poda, Crustacea, Belemnites, and fish and reptilian remains of secondary 
In an adjoining quarry to the above Mr. Moore found a softer infilling, 
three cart-loads of which he removed to his residence, and found therein 
teeth of the Microle-des, the oldest known quadruped ; various reptilia, 
including Placodus and Thecodoutosaurus ; more than 50,000 teeth of the 
Lophodus, together with an immense number of other organic remains, 
from the age of the Carboniferous Limestone to thcit of the Inferior Oolite, 
though they appeared chiefly to have been derived from the bone-bed of 
Kboetic age. 
In the upper portions of some of these fissures, galena, sulphate of 
barytes, and iron ore were occasionally present, which showed that in 
these cases the minerals must necessarily be of secondary age. Desirous 
of more fully investigatiug this point, the author examined the mineral 
deposits of the Mendips, in doing which he descended the Charter House 
Mine, and obtained very interesning results. The lead mines of this dis- 
trict had been extensively worked in the Eoman period, the slags and 
slimes they left being now profitably re-worked. The vein-stuff of the 
above mine was found to be very varied in its character. At one point it 
was almost entirely composed of disjointed encrinital stems, with a few 
corals, all much abraded b}^ the action of water. At a depth of 175 feet, 
where the working had ceased, there occurred a deposit of blue marl eight 
feet in thickness, which yielded 7^ per cent, of lead ore. In this marl he 
found organic remains in the greatest abundance, and eventually succeeded 
in obtaining about 130 species, a few being derived from the Carboniferous 
Limestone, though the greater number were of secondary age. They con- 
sisted of an Ammonite, Belemnites, ten species of Brachiopoda, including 
Zellania — hitherto found only by the author in the Upper Lias and the 
Inferior Oolite ; also, Thecideum, Crania, Lingula, Ehynchonella, Spirifer, 
etc. Of univalves, there were about thirty species ; of Foraminifera, fif- 
teen ; fisli remains were abundant, consisting of teeth, scales, and bones of 
probably fifteen species. In this clay were also blocks of stone containing 
shells and pieces of drift-wood, tlie latter having been converted into jet. 
From these facts it became evident that the ^Vtendip lead-veins had been 
within the influence of the ocean during the secondary period, and that 
the minerals they contained could not be of more ancient date. 
The district arouud Bristol was then noticed, and it was shown that 
precisely similar phenomena occurred there in the Carboniferous Limestone. 
At Cliftou, the Thecodontosaurus had been found ; and it was urged that 
