292 



THE GEOLOGIST. 



obscure fussils 4. The Yellow Sandstone, rich in remains of Holoptydims and 

 other fishes, and about 300 or 400 feet in thickness. This sandstone is seen to 

 rest unconformably on the middle or Clashbinnie series of the Old Red at the 

 northern opening of the Den, and at the southern end is unconformably overlaid 

 by the carboniferous rocks. It is also exi)osed beneath the lower coal-series of 

 Cults, the Lomonds, Binnarty, and the Cleish Hills. It is seen also in Western 

 Scotland (Renfrewshire and Ayi'shire), and also in Bemickshire and elsewhere in 

 the south, with its Pterichthyan and Holoptychian fossils. In the author's opinion 

 it is entirely distinct from the " Yellow Sandstone" of the Irish geologists. 



At Dura' Den the yellow sandstone in some spots teems with fossil fish, especially 

 inonethm bed. In 1858 a remarkably fine H olopty chins Andersoni was met with ; 

 and this, with many other specimens, fully bears out Agassiz's conjectures for 

 completing the form and details of the fish wiiere his materials had been insuffi- 

 cient. Dr. Anderson also offered some remarks on the Glyptopomus minor ( Agass.), 

 the specimen of which was obtained from this locality ; and he drew attention to 

 two apparently as yet undescribed fishes also from Dura Den. 



[Several specimens from Dura Den, and drawings, were exhibited by the author. ^ 

 And a collection of specimens fi'om the Society's Museum, and a selection from the 

 original di'awings illustrating M. Agassiz's Monograph, were also exhibited.] 



June \st, 1859. — 1. " On the Sinking for Coal at the Shireoaks CoUiery, near 

 AVorksop, Notts." By J. Lancaster, Esq., and C. C. Wright, Esq., F.G.S. 



In two shafts sunk for the Duke of JSTewcastle, on the north-west side of hi 

 estate of Worksop Manor, it was found that the Permian beds have a thick- 

 ness of 166 ft. ; the uppermost consisting of thin sandstones and marls (54 ft ) ; then 

 hard yellow hmestone (54 ft.), blue limestone and shale (20 ft.), blue shale (33 ft.), 

 and soft gritstone, probably equivalent to the "Quicksand" of the north (5 ft.). 

 Below the gritstone the coal-measures commence with 5 feet of blue shale, in 

 which there are four bands of ironstone ; another band, 15 inches thick, lies 

 immediately below. This iron-ore is chiefly in the state of peroxide, gives an 

 average of 42 per cent, of metallic iron, and promises to be of great economical 

 value. The fii'st seam of coal (2 feet thick, and of inferior quality) was cut at a 

 depth of 88 yards. Four yards below this is a compact sandstone 66 feet thick. 

 The sinking through this rock occupied 20 months ; each pit made 500 gallons of 

 water a minute, which was stopped in detail by cast-iron tubing. The pressure 

 from the gas at the bottom of this thick rock was at times as high as 210 lbs. per 

 square inch, but is now about 196 lbs. per square inch. Shales, with coal-seams 

 and bands of ironstone, all thin or of inferior quality, were met with in the next 

 170 yards. At 346 j^ards the first thick coal was cut, and found to be 4 ft. 6 in. 

 thick, and of good quality. This is considered to be the " Wathwood Coal." 

 The "Top Hard Coal" was cut at a depth of 510 yards, and found to be 3 ft. 10 in. 

 thick: the strata intervening between this and tlie "Wathwood Coal" were found 

 to have much the same characters and thickness as they are known to have else- 

 Avhere. The sinkings were commenced in JMarch, 1854, and perseveringly continued 

 until their completion on February 1st, 1859. Altogether, 37 feet of coal were 

 passed through but only four seams are of Avorkable thickness. The authors of 

 this communication remark that the district appears to be remarkably free from 

 faults, that the dip decreases considerably towards the east, and that the " Top 

 Hard Coal " appears to thin out eastwardly. 



[This paper was illustrated by carefully prepared sections (vertical and hori- 

 zontal), and by specimens of the ironstones, &c.] 



2. " Notes on the Geology of Southern Australia." By A. R. C. Selwyn, Esq., 

 Director of the Geological Survey of Victoria. In a Letter to Su' R. I. Miu-cliison, 

 F.G.S. 



Mr. Sehv;y^l remarked that, as to the impoverishment of auriferous veins in 

 de])th, the only evidence of such being the case in Victoria is the gTeat richness of 

 the older drifts ; for, iudging from the large size of the nuggets sometimes found 

 HI the gravels, compared with that of the'nuggets met mtli in the gold-bearing 

 quartz-veins (usually from about 4- dwt. to i oz., though occasionally as much as 

 12 ozs. or even 13 lbs.), the upper portions of the veins, now ground down into 

 gravel, were probably richer in gold (as formerly suggested) than the lower parts, 



