PROCEEDINGS OF GEOLOGICAL SOCIETIES. 
365 
long lines of depression accompanied bj long lines of elevation, often, as in the 
case of the British Isles, Spain and Portugal, and elsewhere, belonging to parts 
of huge polygons broken up into small ones, as if the surface of the earth had 
once formed part of a basaltic causeway. 
Several charts, plans, and drawings were provided by the autiior in illustra- 
tion of the paper. 
2. "On the Ludlow Bone-bed and its Crustacean Remains." Bv J. Harlev, 
M.B. Communicated by Prof. T. H. Huxley, Sec. G.S. 
Of the two bone-beds occurring near Ludlow, the lower one (seen in Lud- 
ford-lane and on the north-east slopes of Whitecliff) is that which has supplied 
the author with the materials for this paper. Besides spines, teeth, and 
shagreen-Hke remains of fish, the author finds in the Ludlow bone-bed three 
kinds of minute organisms : 1st, conical bodies, the same as the " Conodonts" 
of Pander ; 2ndly, bodies somewhat like the crown of a molar tooth ; 3rdly, 
oblong plates. . All these bodies possess the same chemical composition and 
microscopical structure, w^hich is decidedly Crustacean. With Pteri/gotus they 
do not appear to have any relationship, unless some are the stomach-teeth ; nor 
do they show any alKance vvith Trilobites ; but with Ceratiocaris they have a 
great retemblance as to structural characters, and some of them were probably 
the minute secondary spines of the tail of that Phyllopod. The plale-like 
forms might have belonged to Squilloid or Limuloid Crustaceans. To facilitate 
the recognition of these bodies Mr. Harley places them all in one provisional 
genus with the name of Astacoderma. A letter from Dr. Yolborth to the 
author was also read in confirmation of Mr. Harley's opinion that these bodies 
are identical with Dr. Pander's " Conodonts." Numerous original drawings 
illustrated the paper. 
3. "On the Old Red Sandstone of Forfarshire." Bv James Powrie, Esq., 
F.G.S. 
The author described the series of stratified rocks belonging to the Old Bed 
Sandstone, upwards of three thousand feet in thickness, stretching southward 
from the Grampians to the coast of Pifeshire. 1st. Dark red grits (with corn- 
stones and flagstones) equivalent to the English " tilestones." 2ndly. Thick 
conglomerates and the Arbroath paving-flags. Fierygotus anglicus, StylonuruSy 
'Parka dedpiens, Cephalaspis, Diplacanthus gracilis, and other fossils belong to 
this part of the series. 3rdly. Thick-bedded red sandstone (with cornstone) 
Cephalaspis and Pferaspis. 4thly. Soft deep-red sandstones. 5thly. Spotted 
marls and shales : these beds are the uppermost, and may be the equivalents of 
the Holoptychian beds of Clashbinuie. The author showed that between the 
Grampians and the trappean hills of Bunnichen and Bunbarrow the series forms 
a great syncline ; and between these hills and the sea the older beds are twice 
again brought to the surface ; and he believes that the marls and sandstones at 
Whiteness are not unconformable, as Sir C. Lyell has represented them in his 
published section. 
4. The Secretary gave a brief account of the discovery of an exposure of 
sandstone strata with two bands of clay full of calcareous nodules containing 
plentiful remains of Coccosteus, Glyptolepis, and other fishes belonging to the 
Old Bed Sandstone, in a burn about two and a half miles from the Manse at 
Edderton, Ptoss-shire, on the south side of Durnoch Pirth. This information 
was contained in a letter from the Rev. J. M. Joass, of Edderton, communicated 
by Sir R. 1. Murchison, Y.P.G.S. 
5. " On the Outburst of a Volcano near Edd, on the African coast of the 
Red Sea." Bv Capt. R. N. Plavfair, R.X. Communicated by Sir R. 1. 
Murchison, Y.P.G.S. 
At Edd, lat. 13 deg. 57 min. north, long. 11 deg. 4 min. east, about half-way 
between Massouah and the Straits of Bab-el-Mandel, earthquake-shocks 
