208 
THE GEOLOGIST. 
the London clay are notoi iously difficult to keep ; the great thing seoms to be the 
entire exclusion of moist air, either by ■varnishing or by putting the specimens in 
close-stoppered glass bottles. Total immersion in oil, naptha, and even in water, 
has been found in some cases effective, (ilycerine is worthy of trial. 
Localities fob Fossils abound Londox — " Sir, — My reason for troubling you 
with this note is that I am anxious to obtain some information respecting the 
bcft localities near London for obtaining fossils. Your reply would much assist 
me in the study of geology — a science of which I am particularly fond. Apolo- 
gising for intruding upon your valuable time and space, I am, S:c., Amatob 
NATuiiiE, davendish-square." — The following are the chief localities around 
Loudon: — For the chalk, Gravesend. Purfleet, Charlton, Erith, and Grays; for 
London clay, Highgate, Hampstead, Southend Clitf, and Isle of Sheppey; for other 
Tertiaiies, Woolwich, Charlton, Erith, Bromley, Loam- pit Hill, Lewisham, and 
S^dculiam — especially the railway-cuttings near the Crystal Palace: for (mam- 
maliferous) brick- earth and gravel, llford, Brentford ; for northern drift, Muswell- 
hill. 
First Appearance in Existing Animals and Plants — " Sib, — Can you inform 
meat what period existing species of the four vertebrate classes first appear? 
Also when we first meet with exis;ing plants. Yours, &c., C. Evans" (Hampstead) 
—Some geologists will not hear of the presence at the present period of animal- 
species older than the Pleistocene. Others think it quite possible existing species 
may be traced farther back in the series of geological ages. Indeed, as examples, 
amongst some few others, Terebratula caput-scrpenlis of our seas is quoted as being 
the same species as T. striata found in the London clay, and as probably iden- 
tical with T. striatida of the chalk. But we must always recollect that in shells 
we have to do with the covering only, and not the animal Of plants we cnunot 
say much in this respect. The remains usually known in the fossil slate, 
namely, leaves and wood, are of no use in the determination of species; the really 
essential parts of specific value, the fruits and flowers, are comparatively rare. 
In the ease of some of the simple Diatomactse, it seems to be, however, absolutely 
proven that, as in the case of Foraminifera, some of the same species or varieties 
now living have existed through enormous periods of time; some of the latter being 
found in the Ternary, Cretaceous, Liassic, and even in the Mountain Limestone 
beds. This subject has been illustrated by Messrs. Parker and Rupert Jones, in 
the " Annals of Nat. Hist., 1857.'' Of the species of mammals, all those 
determined as being .specifically the same in the recent and the fossil state are cf 
Pleistocene jage, such as the Fehs catm, from Grays, Fdis leo, from Brentford, 
J/efe« tazus, from Kent's Hole. Remains of many existing animal forms are 
consiantly met with also in turbaries and peat-bogs, in the still older gravels of 
Brentlbrd, Grays, &c., and in the cavern-deposits, probably al.so of the same age aa 
the last ; but beyond the Pleistocene Tetiai'ies no existing spec ies, to our know- 
ledge, has been recognized. Some bird- remains from the cavern accumulations have 
been referred to lark, duck, falcon, &c. The singular recent fish JIallotus villostis, 
or Capellan, is found abundantly in clay-nodules on the coast of Greenland and in 
New Hampshire. Not much is known of the formation to which these nodules 
belong, but it is referred to the Pleistocene clays. We do not know any other 
example. Of reptiles we remember only the Gangetic crocodile or gavial, and the 
land turtle of the Sub-Himalayan deposits, which, it is said, cannot be dis- 
tinguished from the species now existing in India. These reptilian remains appear 
to be ccmmingkd with Miocene animals. 
Oak Tree found in the Tynb.- — The conservators of the river Tyne were, for 
some yo.ars, actively engaged in deepening the river, and removing obstructions to 
the shipping ; one of the most formidable bars wh ch had long defied their 
exertions, was Cockrane Sand, opposite to Heaton Drop, about five miles below 
Newcastle. In November, 18-18, in the removal of this sand-bank, under the 
direction of Mr. Brooks, engineer, it was discovered that the cause of obstruction 
arose from the presence in the bed of the river of a stupendous oak tree, which, 
alter being skilfully and securely chained to two barges at low tide, was, at high 
water, weighed up and carried to Newcastle, where, by means of a powerful crane, 
