74 
THE GEOLOGIST. 
around them, and both they, and the nodules subsequently, have appa- 
rently been not uncommonly subjected to a considerable amount of rolling 
and degradation. Numerous kinds of shells are common in these nodules, 
as are bones of pterodactyles and other reptiles. Our attention has lately 
been drawn to very numerous fragmentary remains of turtles, consisting 
chiefly of tlie crania and lower jaws, with numerous fragments of the cara- 
pace, ribs, and many vertebrae. The predominance of the skulls and lower 
jaws in the collection we refer to, which was made by Mr. Farren, of Cam- 
bridge, and has just been purchased by Mr. -Gregory, is probably the mere 
accidental result of the collecting of what might be deemed saleable speci- 
mens, or that these portions being the most readily recognized, attracted 
attention, while the other fragments of the limbs and body, more ob- 
scure in their aspect, were left in nodule-heaps. Professor Owen has made 
out distinctly, not less than four species, namely, — CJielone sulcimentum, 
C. altimentum, C. unciinentum, and C. depresshnenium. But the point to 
which wo want to draw attention is, the district and the land-shores on which 
these turtles lived. The Upper Greensaud is a marine deposit, and the 
beds at Cambridge seem closely allied to the grey chalk, especially as that 
member of the cretaceous group appears developed in Kent and Sussex, 
and therefore should have been formed under some considerable depth of 
water. 
jN^ow all the Chelonise are of littoral habits, and as these greensand- 
nodules, like the phosphate-nodules from the Gault and Lower Greensand, 
and all the other deposits from which we have seen them, frequently have 
oyster and other shells attached to them, it would seem that they had been 
brought to a hardened state before they were imbedded in the strata where 
we now find them. We ought therefore to look to some of the older for- 
mations as the land whose coasts they inhabited. 
The turtles of the Wealden have never been properly collected, and it 
is with a view to inducing some one to take up the search for them and 
their comparison with these Upper Greensand fragments, that we have pub- 
lished this note ; for to the Wealden lands a priori, it is that we should be 
inclined to turn for the shores on which these ancient turtles lived, and 
from which their concreted remains were probably washed down by the 
tides and currents into the lower depths of the Wealden sea, where some 
portions of the Upper Greensand were contemporaneously being deposited. 
Fossil Feather. — From the lithographic stone of Solenhofen, in Bava- 
ria, Hermann von Meyer has obtained a fossil impression of a feather, on 
the two opposite surfaces of a split slab. This he cannot distinguish from 
the feather of a bird. This interesting relic will be described and figured 
in the " Palcfiontographica." 
Devo>'ian Fossils. — Errata. In the title, for Geological read Geo- 
graphical. Page 19, line 14, for Devonshire read Devonian. Page 20, 
line 14, for era read area. Page 20, line 5 from bottom, for Table IV. 
readT'dhle V. — W. Pemgelly. 
FOUEIGT^ CORRESPONDENCE. 
Professor Schroetter communicated to the Imperial Academy of Sciences 
of Vienna, on the I7ih October, that a litha-mica, containing more than 
three per cent, of rubidium, caesium, and lithium, has been lately found in 
Saxony, and that samples of it had been sent to Professor Bun sen, at Hei- 
