310 
THE GEOLOGIST. 
The coast from Stonehaven to Aberdeen affords a most interesting exposure 
of the structure of the Grampians. The Old Red Sandstone of Stonehaven 
is succeeded by the clay-slate of Carron Point and that in turn by mica-slate 
and gneiss, all of them frequently traversed by dykes of trap, porphyry, quartz, 
and granite. This subject is noticed in Nicofs "Guide to the "'Geology of 
Scotland," p. 180, &c., and in the Geological Society's Journal, vol. xi., p. 544. 
Stereognathl's OpLiTicus FROM Stonesfield Slate. — Dear Sir, — I think 
that most of your readers* will be glad to hear of the discovery of a second 
specimen of the hitherto unique jaw of the Stereognathus Ooliticus. Such a 
specimen I lately had brought to me by a young friend among other fossils for 
naming. On obtaining it from hrm, I showed it to my friend Professor Huxley, 
who very kindly worked the specimen out from the enclosing matrix. At first 
he believed it to be a new species altogether ; but he tells me now, from 
further examination and comparison with the only other known specimen that 
he considers this also to be the Stereognathus Ooliticus. It should be re- 
marked that my specimen has one more tooth than the original fossil, although 
the crowns of the little molars are not in quite so perfect a state of preserva- 
tion. There is about the same amount of the jaw-bone preserved, which is 
iclearly exposed, and in which the double fangs of the teeth (so characteristic 
of the mammalian class) may be seen embedded. The locality froln which my 
specimen comes is rather uncertain ; but shells and other fossils which were 
associated with it, and the appearance of the matrix itself prove it to be from 
the Stonesfield Slate. — I remain, sir, yours &c., E. Ray, Lanbeater. 
Geology of Arabia. — Sir, — CoiTld you kindly inform me, through the 
medium of your invaluable " Notes and Queries," what the principal geological 
features of Arabia consist in ; or refer me to any book, paper, or pamphlet 
where I could find anything on the geology of that country ? Also whether the 
deserts in the interior are of tertiary for'nation or not ? If you could answer 
me these questions you would much obKge me. — Yours, &c., M. R. A., New- 
port PagnaU. 
In the Journal of the Royal Geograj^hical Society, vol. iv., p. 192, 1834, is 
a paper on the Southern Coast of Arabia and the shores of the Red Sea, in 
which geological observations are plentiful. 
The south-east coast of Arabia has been treated of geologically (hj^ Dr. H. 
J. Carter), in the Journal of the Bombay Branch of the Asiatic Society, for 
January, 1852. 
With respect to geological maps of Arabia, we may mention the " Geognos- 
tische Karte des Petraischen Arabieu (by J. Russegger, 1847, Schweizhart, 
Stuttgart). 
The chief geological features in Arabia appear to consist of — 1, granitic and 
metamorphic rocks (especially near the coast-line and in the Sinai district) ; 
2, sandstone of undetermined age ; 3, cretaceous rocks of considerable extent ; 
4, nummulitic and other tertiary strata in abundance ; 5, post-pliocene sands, 
some of them rich in shells and foraminifera : some at least of the desert-sands 
belong to the last. 
Geology of Yorkshire. — Dear Sir, — It is a regular custom for a few of 
us in this district, during the summer season, when we are favoured with a 
week's recreation, to visit some district in search of its geological treasures. 
We are this year anxious to visit the east-coast of Yorkshire, but more parti- 
cularly Whitby and Scarborough ; none of us, however, are acquainted with 
the formation of that district, and from the books which we have we can obtain 
very Httle information. 
If you or some of vour learned correspondents could, through the medium 
of your most valuable publication (which is taken by several, and read by 
every member of our society), give us some information as to the rocks of the 
