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6. Red and Purple Shales and laminated Rocks. Very large heads of Cephalaspis have been obtained here, probably Murchisoni, and also heads of one or more new species of Fish

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7. Blue muddy soft frangible stone of the Lower Ludlow character. It contains a few Lingulas, and I found here a small Trilobite above the uppermost part of the Upper Silurian formation ...

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Red Marls and thin band of Old Red Sandstone

9. Grey Sandstone embedded in blue mud. Has yielded nothing but one Lingula. This is just opposite the western entrance to the tunnel, but it is understood many feet of the tunnel will be removed at an early period, and the entrance will then be so much further eastward than it now stands. Consequently the entrance to the tunnel is not a reliable landmark*

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10. Red Marls, with strong bands of Old Red Sandstone. Almost devoid of fossils of any kind

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11. Silurian band of Soft Blue Stone, with a few Lingulas 12. Red Marls and Shales, without fossils ...

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13. Brownish-grey band of soft Silurian Rock with large heads of Cephalaspis, new species, Auchenaspis with part of the body scales, never before

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14. Old Red Sandstone. Very hard tabular band.

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Cephalaspis Bed. Fine grained Old Red Sandstone of compact structure,
very full of Cephalaspis, consisting chiefly of the new species peculiar
to Ledbury, the head shield ending abruptly without cornua.
also may be seen the body and tail of Auchenaspis Egertonii, never
found until the year 1882. Here also are several species of Lingula ...

17. Blue Silurian Shales. Pterygotus.

18.

Red Shales and Marls, with a few narrow bands of Old Red Sandstone. The base of this formation is a band of very dark red shaly clay, having laminations of varying thicknesses with wavy surfaces, whereon are accumulated many semi-spherical concretions varying from a quarter of an inch to an inch in diameter. These may be worm casts, but I have not completely satisfied myself on that head. Except these, there are no fossils

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19. The Lingulu Bed of Greenish-grey Muddy Shales, about four feet thick at the base, i.e. the level of the present work, diminishing gradually to a point, the upper end being retroverted westward for a distance of several feet, the retroverted portion lying horizontally on the red marly clay wherein it is enveloped to its termination. The uppermost parts of these shales are so soft and muddy in structure as to be easily soluble in water; the lower portion is harder. Both

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* The removal of the western entrance of the tunnel to a position many yards further east is now in process of execution. (H. C. M., November, 1898).

Top of parapet wall of tunnel, 1885.

THE PASSAGE-BEDS, LEDBURY, HEREFORDSHIRE, BETWEEN THE OLD RED SANDSTONE AND THE UPPER SILURIAN.
CAMERA POINTING WEST, SHOWING THE EXPOSED EDGES OF THE BEDS FACING SOUTH.

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From a photograph by Alfred Watkins, taken 1884-1885.

are almost or quite homogeneous. They lie in a nearly vertical position, with a dip slightly westward immediately under, but entirely unconformable with, the clay shales just described. For many superficial square yards large Lingulas abounded in masses, and portions of Pterygotus were also found. These probably would have been tilestones if they had become sufficiently hard, and are the equivalents of the so-called Tilestones of Murchison

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20. Red Marls lying between thin bands of Old Red Sandstone. Without fossils

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21. Grey Silurian Shales of the Downton Sandstone character. Without
fossils
Old Red Shales and Marls. Without fossils ...

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Laminated Silurian Shales, with a narrow band 12 inches wide of Downton Sandstone. These bands are vertical, the upper portion being very much retroverted. Without fossils

24. Old Red Sandstone Shales and Marls, overlaid the whole distance by a downthrow of broken up fragments of Downton Sandstone, intermingled with scraps of Old Red. Without fossils...

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This is the true base of the Passage Beds.

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UPPER SILURIAN.

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25. Downton Sandstone. All that is in sight is retroverted westward, and in that position lies upon the Old Red Sandstone. Small Chonetes may be found here. The entire absence of the Bone Bed from its place here is worthy of notice... 26. Upper Ludlow Shales. At a distance of 40 feet below the Downton Sandstone there is a band of hard stone eight inches wide, nearly vertical, very much stained with ochre, and resembling Downton Sandstone, but it does not belong to that formation. The whole of the last 40 feet is nearly vertical at the base, and all of it is retroverted. About 27. Aymestry Limestone. At a distance of 113 feet from the top of the Aymestry Limestone, or 27 feet due east of the corner of the Frith Wood may be found a very interesting occurrence of the bed containing Pentamerus Knightii. These beds at Aymestry, whence their name is taken, are very many feet in thickness; at Ledbury the Pentamerus bed is only one inch thick. The fossils which at Aymestry are nearly as large as a man's fist, have dwindled here to little more than the dimensions of a thumb nail. When the Ledbury railway was first made Pentamerus Knightii was found in stone which came out of the tunnel, but the exact position of the bed was not known, and has never been discovered since until now

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28. Transition Beds. It is impossible to draw a line of demarcation between the base of the Aymestry Limestone and the top of the Lower Ludlow. I have therefore called these Transition Beds

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29. Lower Ludlow.

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