PROCEEDINGS OF GEOLOGICAL SOCIETIES. 



long lines of depression accompanied by 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 author in illustra- 

 tion of the paper. 



2. "On the Ludlow Bone-bed and its Crustacean Remains." By J. Harley, 

 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-like 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, which is decidedly Crustacean. With Pterygotus they 

 do not appear to have any relationship, unless some are the stomach-teeth ; nor 

 do they show any alliance with Trilobites ; but with Ceratiocaris they have a 

 great resemblance as to structural characters, and some of them were probably 

 the minute secondary spines of the tail of that Phyllopod. The plate-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." By James Powrie, Esq., 

 F.G.S. 



The author described the series of stratified rocks belonging to the Old R,ed 

 Sandstone, upwards of three thousand feet in thickness, stretching southward 

 from the Grampians to the coast of Fifeshire. 1st. Dark red grits (M 7 ith corn- 

 stones and flagstones) equivalent to the English " tilestones." 2ndly. Thick 

 conglomerates and the Arbroath paving-flags. Pterygotus anglicus, Stylonurus, 

 Parka denipiens, Cephalaspis, Diplacanthus gracilis, and other fossils belong to 

 this part of the series. 3rdly. Thick-bedded red sandstone (with cornstone) 

 Cephalaspis and Pteraspis. 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 Clashbinnie. The author showed that between the 

 Grampians and the trappean hills of Bunnichen and Bunbarrowthe 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, Boss-shire, on the south side of Durnoch Firth. This information 

 was contained in a letter from the Rev. J. M. Joass, of Edderton, communicated 

 by Sir R. I. Murchison, V.P.G.S. 



5. "On the Outburst of a Volcano near Edd, on the African coast of the 

 Red Sea." By Capt. R. N. Playfair, R.N. Communicated by Sir R. I. 

 Murchison, Y.P.G.S. 



At Edd, lat. 13 deg. 57 min. north, long. 41 deg. 4 min. east, about half-way 

 between Massouah and the Straits of Bab-el-Mandel, earthquake-shocks 



