350 



THE GEOLOGIST. 



Leaving this interesting inquiry to be fully treated of by some of our cor- 

 respondents who may have already turned their attention to the subject, we 

 may suggest that the slow process of rubbing stones, first rudely fashioned by 

 fracture, into definite shapes with smooth surfaces by the friction of one piece 

 on another, was probably the actual process of manufacture, however long a 

 time it may have required. The hole may have been produced by the slow 

 grinding of pieces of flint into the stone, possibly by means of some rude 

 revolving apparatus. At all events the manufacture of these hammer-heads 

 must have been extensively carried on throughout the country, especially in 

 the midland and northern countries, whence specimens of almost elaborate 

 workmanship have been not unfrequently obtained. 



Mr. Thomas Wright, the eminent antiquary, we know entertains the opinion 

 that the better formed of the antique stone implements were contemporaneous 

 with those of metal, and were made with metal tools. 



Geology op Cornwall. — In our reply, page 199, to the inquiry respecting 

 the geology of Cornwall, references to Sir Henry De la Beche's excellent 

 " Report on the Geology of Cornwall, Devon, &c.," and to the Rev. Professor 

 Sedgwick's "Memoir on the Slate Rocks of Cornwall and Devon," in the 

 Journal of the Geological Society, vol. viii., p. 1, were accidentally omitted. 



Geology op Reading. — Dear Sir, — I read in the April number of the 

 " Geologist," page 151, in Mr. Charles Rickman's letter, some reference to 

 the geological series of deposits in this neighbourhood. We are referred to 

 the Quarterly Journal of the Geological Society for further information, but I 

 fear it is not in my power to get that ; so may I, as a constant subscriber ever 

 since the first issue of your valuable magazine, beg of you to give us a little 

 information occasionally as to the strata and fossil varieties in this neighbour- 

 hood. The only one I have found has been a large oyster in the chalk beds of 

 Cavershara. 



I hope you will excuse my taking this liberty. — Yours much obliged, A. H. 

 Reading. 



If we are not favoured by some correspondent with a detailed account of the 

 chalk, Thanet sands, Woolwich beds, London clay, and gravels of the Reading 

 district, we will take an early opportunity of fulfilling our correspondent's 

 request. But we hope that this interesting county will find its own geologist. 

 Tlie neighbouring district of Newbury, consisting of very similar formations to 

 those of Reading, has been described in a little pamphlet by Mr. T. Rupert 

 Jones (Geol. Hist., Newbury, 1854. Blacket, Newbury; Lovejoy, Reading.) 



Geology op Sligo. — I see with surprise that you have in last " Geologist,'* 

 page 317, mistaken the band of mica-schist and other hard old transition rocks 

 which form the Ox mountains in Sligo and Mayo for Old Red Sandstone. The 

 latter is very thin, and but rarely seen in the neighbourhood of Sligo, according 

 to Sir Richard Griffiths. 



Tlie limestone of Sligo is peculiar and unlike the great mass of that forming 

 the centre of Ireland ; it seems to be a great development of the lower beds 

 resting ii])on certain others (sandstones) conformably, concerning which there 

 is a cUfi'crcnce of opinion, viz., as to whether they are reaUy below the lime- 

 stone, or arc iiitcrstratified with it at a considerable height in the formation. 



I liad ho])cd to have investigated this point when I was last at home, but 

 Avas prevenled by the weather. Now, however, we may perhaps hope to hear 

 soincthiiig of the rocks in that country from your correspondent, particularly 

 if ho should be connected with the railway which is being made, and will cross 

 bolh the range of older rocks and that of the Curlew mountains, formed, 

 I believe, in some places of Old Red Sandstone. — Yery truly yours, 

 A. B. Wynne. 



HiBBERTi ON EossiL FiSH OP BuRDiEiiousE. — SiR,— Can you inform me 



