302 
THE GEOLOGIST. 
work to any gentleman who would devote his leisure to them. And 
tlie Devil's Bridge, Aberystwith, should be ransacked for fossils; they 
are to be found there, yet the age of these rocks is very imperfectly 
known. 
4. The Cornstones of the Old Eed have some good observers among 
them ; but there is a great deal yet to be done in these, while there 
cannot be too many hammerers upon the transition-beds between the Old 
Eed and Upper Silurian. 
5. The Carboniferous rocks have been well studied, and nothing 
seems wanting but to follow up, for other districts, the patient work 
that Dr. Bevan is doing in South Wales, and ascertain, for all the coal- 
fields, the distribution of the plants in the various parts of the series. 
Now that the Survey-maps are so far advanced, this is comparatively 
easy, since no one can be in doubt about the particular beds he is at 
work upon. 
6. Mr. 0. Eoberts' communication, p. 253 of your last number, 
opens a subject well worth patient investigation — the vegetable con- 
tents of our own Permian strata, especially the lower beds. While 
these beds on the Continent are full of peculiar species, in good preser- 
vation, we, in England, hardly know a dozen specimens of any value 
from them. 
7. Again, where is the representative of the Muschelkalk, or any of 
its fossils, in Britain ? 
8. The contents of the Inferior Oolite Sands are yet only partially 
known. 
9. The transition -beds between the Wealden and the Lower Green 
Sand, and especially the true relations of that remarkable bed the" 
Chloritic Marl (Craie Chloritce) of the south-east of England, whether 
with the Chalk Marl above or tho Green Sand below, are subjects of 
great interest. These ought to undergo a rigid examination. 
I have only sketched a few of the many points which might bo 
attempted during this present summer by iield-clubs, or by private 
geologists working for their own amusement. Perhaps if I were to 
specify two of the more interesting points which deserve notice, I 
should say — 
First. The contents of the Permian strata in the central counties 
where the magnesian limestone is absent. Their boundaries are laid 
down in our new geological maps. 
Second. A full list of fossils from the beds which connect the Car- 
boniferous with the Devonian system. On this subject I hope to send you 
a further communication, and can only say, that careful collections made 
on the two sides of the great Culm-basin of Devonsliirc, viz., at Barn- 
staple, Xorth Devon, and at Petherwyn, in Cornwall, would produce 
good results. AVc know something of the contents of these from the work 
of Professor Phillips, and the still earlier researches of Sedgwick and 
Murchison; but accurate details are wanted from both localities. The 
old lime-(iuarrics at Petherwyn, and more especially the fossiliferous 
slates associated with them, will require long and continued search 
