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extremity the coal beds rise from beneath the sea. The area is thus 

 a great synclinal trough, filled with an enormous thickness of coal- 

 bearing strata. The permian and triassic rocks are rudimentary, and 

 there is no great body of carboniferous limestone at the base of the 

 series, as in most other countries ; and this constitutes a second 

 peculiarity of the Scottish field. The boundaries are formed through- 

 out by Devonian rocks, which attain an enormous development along 

 the north-west border ; but on the south-east form a narrow and in- 

 terrupted zone, so that trap ridges and dikes alone, in many parts, 

 cut off the coal strata from the great southern tract of silurian rocks. 

 Limestone, with all the usual fossils which characterize the carboni- 

 ferous period, does indeed occur, but not as a well developed and 

 continuous base ; nor has the millstone grit of England been hitherto 

 established as a member of the Scottish series. It may yet be 

 found possible to prove its existence within the area ; and at a still 

 lower level, certain sandstones and shales on the line of junction 

 with the undoubted old red sandstone, may turn out to be on the 

 true horizon of the lower carboniferous limestone. The Ballagan 

 beds seem to us to be such a peculiar group, though by some they 

 may be regarded as the uppermost portion of the Old Bed series. 

 They occur in fine typical development, in the bed of the Ballagan 

 burn, at the base of the waterfall called the Spout of Ballagan, 

 about three miles N.W. of Lennoxtown. They here present a 

 vertical section of about 100 feet in height, and consist of numerous 

 alternations of blue and red shales, calcareous marl, white and red 

 thin-bedded sandstones, and thin courses of limestone. The lowest 

 bed visible is a coarse dark-coloured sandstone containing sedge-like 

 plants resembling calamites, but without joints ; the highest, a thick- 

 bedded yellow sandstone without plants, stretching in below the trap 

 series which extends to the hill tops. The plants must, however, 

 exist in the middle portion of the section, for they occur abundantly 

 in the fallen blocks which strew the river bed throughout. A vein of 

 gypsum, 9 inches wide, and numerous contiguous strings of the same 

 substance, stretch far up the cliff, crossing nearly at right angles the 

 various strata, which have a uniform N.W. dip at an angle of 11. 

 The only fossils met with in this locality are these sedge-like plants, 

 which seem all to belong to one species, and are insufficient to decide 

 the age of the beds. A group of veiy similar character occurs on the 

 east side of the Leven valley, near Dumbarton, in the glens N. and 

 N.E. of Dumbuck hill ; and here a few fish scales have been found, 

 but in so fragmentary a state as to render the species doubtful. The 

 locality is, however, promising, and a careful search for fossils will 

 probably bring species to light which will decide the question, and 



