208 



THE GEOLOGIST. 



the London clay are notoriously difficult to keep ; the great thing seems 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. Glycerine is worthy of trial. 



Localities for Fossils AEouiSD London. — " Sir, — My reason for troubling you 

 with this note is that I am anxious to obtain some information respecting the 

 best 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, &c., Amatob 

 Naturje, (!avendish-square." — The following are the chief localities around 

 London : — For the chalk, Gravesend, Purfleet, Charlton, Erith, and Grays ; for 

 London clay, Highgate, Hampstead, Southend Cliff, and Isle of Sheppey; for other 

 Tei'tiaries, Woolwich, Charlton, Erith, Bromley, Loam- pit Hill, Lewisham, and 

 Sy denham— especially the railway-cuttings near the Crystal Palace ; for (mam- 

 maliferous) brick- earth and gravel, Ilford, Brentford ; for northern drift, Muswell- 

 hill. 



First Appearance in Existing Animals and Plants. — " Sib, — Can you inform 

 me at what period existing species of the four vertebrate classes first appear? 

 Also when we first meet with exisdng 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, Terehratula caput-serpentis 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. striatula 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 cannot 

 say much in this respect. The remains usually known in tlie 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 case of some of the simple Diatomacese, 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 Tertiary, 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 of 

 Pleistocene ^age, such as the Felis catus, from Grays, i^eZis leo, from Brentford, 

 Meles taxus, from Kent's Hole. Remains of many existing animal forms are 

 constantly met with also in turbaries and peat-bogs, in the still older gravels of 

 Brentford, Grays, &c., and in the cavern-deposits, probably also of the same age as 

 the last ; but beyond the Pleistocene Tetiaries no existing species, to onr know- 

 ledge, has been recognized. Some bird- remains from the cavern accumulations have 

 been referred to lark, duck, falcon, &c. The singular recent fish 3Iallotus villosus, 

 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 tui'tle of the Sub-Himalayan deposits, which, it is said, cannot be dis- 

 tinijuished from the species now existing in India. These reptilian remains appear 

 to be commingled with Miocene animals. 



Oak Tree found in ihe Tynb. — The conservators of the river Tyne were, for 

 some years, 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 Cochrane Sand, opposite to Heaton Drop, about five miles below 

 Newcastle. In November, 1848, 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, 

 after being skiltully mid securely chained to two barges at low tide, was, at high 

 water, weighed up ;vad carried to Newcastle, where, by means of a powerful crane, 



