301 
GEOLOGICAL DESIDERATA. 
Points op great interest in the stubt of tue Loxgmyxd, Silurian, 
CAUCO.VIFEROfS, PERMIAN, OOLITE, AND CrETAOEOUS ROCKS. 
Tlie Editor presents the following letter from Mr. J. "W. Salter, 
Palaeontologist to the Government Survey, to the readers of the Geolo- 
gist, with an earnest request that tlie effort he is making, by means of 
this department of this Magazine, to promote the real advance of science, 
may be fully seconded by all to whom these most desirable points of 
investigation may become known. The names of Mr. Prestwich and 
Mr. Salter arc guarantees for the value of the work required to be 
done. 
To the Editor of the Geologist. 
Dear Sit?, — Your correspondent, Mr. Prestwich, has opened tlio 
inquiries which, above all others, appear to me to be suitable to the 
pages of the Geologist. I have long intended to write to you on the 
subject, but am very glad to see our able friend commence it. 
What wo want, in the present state of geology, is ahmdancs of good 
fads, and these can only be collected by the industry of local observers, 
who will communicate these results in a tangible form, available for the 
vi'orkers on particular subjects. If these last will, as Mr. Prestwich 
has done, point out the work, and you, Sir, will undertake 
to condense and tabulate for them the facts collected, the more critical 
and obscure points which still remain as ojjprolria in our British 
geology may be wonderfully cleared up. 
The labour and expense of time which private correspondence (often, 
too, very unsatisfactory) entails upon a student -will be thus saved. 
And then, again, there is no pleasure so great as in working for a 
definite object, with the certaintj' that your results, however small, 
will aid in attaining it. Many a holiday may be most profitably 
occupied (which would otherwise be lost) by confining the attention to 
one bed, or a set of beds, instead of hammering away under a vague 
impression that something is to be done, though you know not exactly 
what. 
The points to be worked at arc numerous enough, and will occur to 
many geologists. 
1. Why should we not have a really fine series of fossils from the 
Longmynd rocks, near Church Stretton? 
2. West of the Stiper Stones, Shrophire, a strip of country, a mile 
wide, should be thoroughly explored for fossils, as there are here beds of 
passage between the Lingula-flags and the Llandeilo rocks, and of the 
greatest geological interest. Shells and Trilobites are abundant. 
3. St. David's Head, in Pembrokeshire, too, wants a good hammering. 
The conglomerate-beds north of the Towy will give a whole summer's 
