536 



THE GEOLOGIST. 



pressed in the direction of the cleavage of the containing rock. The contortion 



is too great to admit of a determination of the species. 



]yj:>iEAi VErs's. — '"'Deae Sib, — Perhaps your correspondent 'J. C. ' will be 

 so good as to particTilarize the examples on which he has come to the conclusion 

 ' that mineral veins, in general, contain more iron in limestone than in siliceous 

 strata.' Many will, I think, be slow to admit this as an axiom, without good 

 proof l>eing fcu-nished, and will recal to mind, as I do, numerous instances of veins 

 in granite and siliceous schists abounding in irou, in the common conditions of gos- 

 san (earthy oxide j, or of mundic (pyrites), and where the productiveness of valuable 

 ores seems to be materially influenced by its presence. In addition, the great 

 mass of copper-ore (copper-pyrites) from our chief British mining-districts is a 

 * double sulphide of iron and cop)per,' so that the quantity of the former metal in 

 very many veins is more than meets the eye. The question opened by your 

 correspondent is a very interesting one, and I hope he will himself contribute to 

 its elucidation by giving the facts, from both the limestone and siliceous rocks, on 

 which he forms his opinion. — Tours truly, Hexet Tho3iIas. — Kennington Park." 



Mjjoiaxiain' Remain's at St. Addeesse. — "Four years since, when I inspected 

 the collection of M. Flambard, at Ingou^oUe (Ha\Te de Grace), I observed in it a 

 fragment of the grinder of an elephant. \^itii very broad plates. The specimen 

 -was found on the neighbouring shore at St. Addresse ; it must undoubtedly have 

 come from the loam- or gravel-capping of the cliffs there, and as I was told no 

 other similar remains had been pre^"iously found in that district, I have thought 

 it worth while to send you a note of this fragment in connection with Mr. Prest- 

 wich's inauiry, — M.'' 



Peeisiocexe Fossils feom Bedeoed. — " Deae Sie, — I have had some fossils 

 sent me fi-om the neighbourhood of Bedford from Odell. Can you tell me what 

 formation the surface-clay in that district is likely to be ? I think the shells are 

 Cyclas obovata, and either Cyrena trigonula or Astarte. — Yours very faithfully, 

 J. B. Canterbury/' — The indication of the fossils named is, that the clay enveloping 

 them is of Pleistocene (the latest tertiary) age. Bedford itself is on the Oolitic 

 formation, which, like other secondary deposits, is there, as very commonly in 

 other districts, covered over by the pleistocene gravels and brick- earths. Search 

 should be made for other shells than those named, and, even more particularly, for 

 elephant and other mammalian bones in this deposit ; such remains being of 

 great value at this moment in the decision of certain very important geological 

 questions. 



Ceocoisite — Ameee — Yaeiation oe Gijle Steeam. — "Sie, — Wi 11 you 

 tell me what the enclosed is ; a piece weighing about four pounds was picked up 

 in a field in Carmarthenshire. The outside presented a dull yellow, worn 

 appearance, as seen on one side of the specimen, but its great weight induced us 

 to break it; when the interior looked like a piece of lead-ore coloured with oxide 

 of irom Would you also kindly insert in the Geologist the following queries. 1st. 

 Amber is supposed to be derived from the resins of extinct coniferse. In the 

 Bath Museum there is a piece of amber containing a fish. How did the fish get 

 into the gum of a tree ? 2nd. It was stated some time ago, that, owing to 

 changes in the Gulf stream, we might expect a succession of warm summers. Is 

 there any oscillation in the current ? If the change is occasioned by the partial 

 filling up of the old bed, how can the change be limited ? WiQ it not go on until 

 the warm current is thrown directly on the British Isles, and then altogether 

 beyond our latitude ?— Ci^rRO." — The specimen received is Crocoisite, a chromate 

 of lead, kno-RTi also as red-lead spar. It is used for a pigment, but the colour is not 

 permanent. The mineralogical tests will be found in "Xicol's Manual of 

 Mineralogy-," page 387, and in other treatises on that science. 



Tbilobites Fouj»-d in tbe Excavation oe the Oxpord and Worcester 

 Railway. — We beg to acknowledge a communication from J. Gray, Esq., F.G.S., 

 of Hagley, inclosing gutta-percha casts of fragments of Acidaspis found in the 

 cutting of the Oxford and Worcester Railway. 



Pbxnant Sandstone. — TMience the term Pennant, as applied at Bristol to the 

 sandstone series between the upper and the lower coal-measures ? — Chaeles 

 Mabtel. 



