486 
THE GEOLOGIST. 
PROCEEDINGS OF GEOLOGICAL SOCIETIES. 
Geglogicai Society of London, November 2, 1859. — Prof. J. Phillips 
President, in the Chair. 
The I'oUowing communications were read . — 
1. " On tlie Passage-beds from the Upper Silurian Pocks into the Lower 
Old Red Sandstone, at Ledbury, Herefordshire." By the Rev. W. S. 
Symonds, F.G.S. 
In t he cutting at the Ledbury Tunnel, on the Worcester and Hereford Rail- | 
way, a series of beds liave been exposed, wliich range from the Upper Silurian ' 
or Downton beds to the Old Red sandstone, including bluish-grey rock witli 
fossU fish, crustaceans, and shells, like those found in the raQway-cutting and 
elsewlicre near Ludlow. The following is the ascending order of the beds ob- | 
served : — 1. Aymestry rock, with Pent.amerus Knightii, &c. (ten feet). 2. ( 
Upper Ludlow rock, with Chonetes lata, &c. (one hundred and forty feet. The 
Ludlow Bone-bed seems to be wanting here). 3. Downton bed, thin (nine 
feet), with Lingula. 4 to 8. Red and mottled marls and thin sandstone (two ] 
hundred and ten feet), with Zw/yw/rt and Pfe;Y/.s:/;M (F). 9. Grey shale and thin 'j 
grit (eight feet), with Cephalaspis and Pteryqotus. 10 and 11. Pui'ple shales 
and thin sandstones (thirty-four feet). 12. Grey marl, passing into red and 
grey marl and bluish-grey rock (twenty feet), with Auchenaspis, Plectrodus, 
CepJidhixpis (?), Oiichtts, Pterygotus Ludcnsis, Lingnia, and a Lituite (?). 
These pass uj)wards conformably into a scries of red maris, with yellowish-grey 
and pink sandstone, containing Pteraspis and CephaJasph, and undoubtedly 
forming the base of the Cornstone-series of the Old Red Sandstone. The 
author remarks that there are other corustoues, namely those of Wall-hills near 
Ledliury, of Poxley, Writfield, &c., which are at least three tliousand feet above , 
the Downton sandstone. He also remarks that, as the word " Tilcstones" is \ 
inapplicable to the Ledbury rocks, lie quite agrees with Su- R. Murcliison in 
replacing it by the term " Passage-beds." 
2. "On the so-called Mud-volcanos of Turbaco, near Carthagena." By P. 
Bernal, Escj^. ; in a letter to Sir R. I. Murchison, P.G.S. 
Turbaco is a village, about fifteen miles from Carthagena, at an elevation of 
about nine hundred and eighty feet above the sea. At a distance of about 
three mUes from the village, and at a higher elevation, in the midst ef a forest, 
are some twenty or tliirty conical hillocks, about eight or ten feet higii, each ' 
with its little crater or orifice, about two feet in diameter. These are filled 
with a muddy water ; and every two or three minutes a sUght noise is heard, a 
bubbling up of air or gas takes place, the muddy fluid runs over, and forms into 
cakes of blue clay. The water is quite cool, nor is there any present or 
anterior marks or vestiges of the action of fire or heat. 
3. " On the Coal-formation at Auckland, New Zealand." By Henry Weeks, 
Esq., coirununicated by the President. 
The district is formed of stratified sandy clays, of Tertiary age ; they vary in j | 
colour from white to hght-red. The white clays contain beds of lignite, vary- | | 
ing from a few inches to several feet in thickness. Sections of these beds are | 
exposed along the banks of most of the tidal inlets with which the district i 
abounds. In some places, near the hills, the Ugnite is seen to rest on trap- ] 
rock ; elsewhere a shelly gravel underlies it. 
At Campbell's farm a whitish sandstone lies on the lignite, and at the junc- I 
