292 
THE GEOLOGIST. 
obscure fossils 4. The Yellow Sandstone, rich in remains of Holoptychim 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 exposed beneath the lower coal-series of 
Cults, the Lomonds, Binnarty, and the Cleish Hills. It is seen also in Western 
Scotland (Renfrewshire and Ayrshire), and also m Berwickshire and elsewhere in 
the south, with its Pterichtliyan and Iloloptychian 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 
in one thin bed. In 18:58 a remarkably fine Hotophjchius Andersoni was met with ; 
and this, with many other specimens, fully bears out Agassiz's conjectures for 
comjileting the form and details of the fish where his materials had been insuffi- 
cient. Dr. Anderson also oft'ered some remarks on the Qli/ptoponius minor (Kgass.), 
the specimen of which was obtained from this locality ; and he di^ew attention to 
two appai'ently 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 from the Society's Museum, and a selection from the 
original drawings illustrating M. Agassiz's J^onograjth, were also exhibited.] 
Jime 1st, 18.59. — 1. " On the Sinking for Coal at the Shireoaks Colliery, near 
Worksoj), Notts." By J. Lancaster, Esq., and C. C. Wright, Esq., F.G.S. 
In two shafts sunk for the Duke of Newcastle, on the north-west side of hi, 
estate of Worksop Manor, it was found that the Permian beds have a thick- 
ness of 1 66 ft. ; the upjiermost consisting of tliin sandstones and marls ( .54 ft ) ; tken 
hard yellow limestone (.54 ft.), blue limestone and shale (20 ft.), blue shale (33 ft.), 
and soft giitstone, probably equivalent to the "Quicksand" of the north (5 ft.). 
Below the gritstone the coal-measures commence with 5 feet of lilue shale, in 
which there are four bands of ironstone ; another band, 1.5 inches thick, lies 
innnediately 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 first seam of coal (2 feet thick, and of inferior quality) was cut at a 
depth of 8S yards. Four yards below this is a compact sandstone 66 feet thick. 
The sinking through this rock occu])ied 20 months ; each pit made 500 gallons of 
water a minute, which was stoppetl in detail by cast-iron tubing. Tlie 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 yards the first thick coal was cut, and found to be 4 ft. 6 in. 
thick, and of good (piaUty. 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 the "Wathwood Coal" were found 
to have nnich the same characters and thickness as they are known to have else- 
where. The sinkings were commenced in March, 18.54, and perseveringly continued 
imtil their completion on February 1st, 1859. Altogether, 37 feet of coal were 
passed through ; but only four seams are of workable thickness. The authors of 
this communication remark that the district appeal's 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 iUustrated 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 Sir R. I. Murchison, 
F.G.S. 
Mr. Selwyn remarked that, as to the impoverishment of auriferous veins in 
depth, the only evidence of such being the case in Victoria is the great richness of 
the older drifts ; for, judging from the large size of the nuggets sometimes found 
in the gravels, compared with that of the nuggets met with in the gold-bearing 
quartz-veins (usually from about ^ dwt. to ^ oz., though occasionally as much as 
12 ozs. or even 13 lbs.), the upper portions of the veins, now ground down into 
gravel, were proltably richer in gold (as fomerly suggested) than the lower parts, 
