552 
THE GEOLOGIST. 
It was found from the careful iuspection of tlie various coal measures, that in 
England the western portions appear to present mechanical indications, whilst 
the eastern portions seemed more to indicate chemical action. In the Kew 
World precisely the reverse was the case, the clicmical action being evident in 
the west, and the mechanical in the east. Passing lotlie European continent, 
he referred to the small coal fields of Belgium, to the three principal deposiis 
in France, to tlie fields of Spain and Portugal ; and then returning castv.ard 
explained the formation of the Prussian and Bohemian coal fields, and 
described the rich deposits of braunkohle which extends across the German 
continent. 
After a brief reference to the coal fields of Africa, discovered by Dr. Living- 
stone, he passed into Asia, and described the deposits of coal in India, and 
then proceeded through Borneo, Lebuan, &c., southward, concluding his re- 
marks on the Old World by describing the coals of New South Wales, Tas- 
mania, and New Zealand. The survey of the New Woi-ld Avas commenced by 
a reference of the coal fields and Albertite deposits of the British possessions 
in North America. Then the great coal fields of the United States were de- 
scribed, and the subject completed by a brief explanation of the nature and 
extent of the deposits about Chili and Valparaiso. 
On the conclusion of the lecture there was an interesting discussion, in 
w/(ich Messrs. Rickard, T. Rupert Jones, Mackie, Lawsou, and Prof. 
Tennant, took part, and Prof. Morris replied to a large number of ques- 
tions, but declined, in answer to the interrogatories of Messrs. Lawson and 
Mackie to state any opinion on the nature of original formation of those highly 
interesting substances Albertite and the Torbanc Hill mineral. 
The President announced that during the session exc wsions woidd be made 
to Tnnbridge Wells or Hastings, Harwich, Cambridge, or Lewes. 
Cambridge Philosophical Society. — October 2S. At the annual general 
meeting of this society, after the election of ofticers, a paper was read by Air. 
Harry Seeley " On the Pen-clay Pormation." 
Extending under the peat of the fen district, and far beyond, is the great 
clay formation. It includes the Oxford and Kimmeridge clays, and an inter- 
vening clay (replacing the Coral rag) which imperceptibly graduates upwards 
and downwards into these deposits. It is for this series of strata, ranging from 
the Great Oolite to the Portlaudian beds, that the term Pen-clay or Pen-forma- 
tion is proposed. The fact of such a succession in some degree interferes witli 
existing vievrs of the division of the lower secondary strata into Upper, Middle, 
and Lower Oolites ; so that henceforth it will probably be found more con 
venient to abandon those terms, and to speak of the secondary formations 
below the Cretaceous series, as Lias, Inferior Oolite, Great Oolite, Pen-clay, 
and Portland-bed. In this district the Pen-clay extends from the line of 
Peterborough to Bedford, across easterly to the line of Ely and Lynn, within 
which limits it has been chiefly studied, though known to have an extensive 
development further south. 
The various sub-divisions were worked out in the country around Elsworth, 
near St. Ives. The village is built on a limestone, to which it gives a name. 
The Elsworth Rock, vrhich consists of three sub-divisions, an upper and lower 
rock, and a middle clay which abounds in Osf/ve MarsJiii. The rock dips to the 
south, and maintains its thickness (fourteen feet) unchanged for the three 
miles over which it could be traced, tliough at that distance the middle clay is 
replaced by sandstone. 
Passing to the north, another rock is met with, at Sr. Ives, and this was 
shown to be 180 feet below tlie Elsworth Rock, coming out from under it, 
being brought up by an anticinal axis, so that further to the north, at Blun- 
lisham, the Elsworth rock is again met with. The St. Ives rock dips to tl;e 
