GEOLOGY Palaeocoma Marstoni, testify, and where J. E. Lee obtained the earliest known fish, Scaphaspis ludensis.^^ Here also have been obtained specimens of Ptery- gotus, Kurypterus, Hemiaspis, and Necrogammurus, and as recently as 1904 several well-preserved star-fishes were obtained, besides plates of Dithyrocaris, large Orthoceratites and various common fossils. Near Kington the Lower Ludlow Shales are exposed in Bradnor Wood, but by far the most important section in the Herefordshire portion of the Ludlow district is at Elton Lane, near Ludlow. While Miss E. M. R. Wood has exhaustively dealt with ' The Lower Ludlow Formation and its Graptolite Fauna ' in the Ludlow and contiguous districts,^' Miss G. L. EUes and Miss S. L Slater have written no less exhaustively on ' The Highest Silurian Rocks of the Ludlow District,' " that is on the Aymestrey, Upper Ludlow, and Temeside Stages. Graptolites occur more or less abundantly in the Ludlow rocks as high as the Mocktree Shales, and these authoresses have used these fossils as much as possible for zonal purposes with very satisfactory results. The Aymestrey Limestone derives its name from the village of Aymestrey, in the neighbourhood of which there are many quarries in the Limestone. It was here that the Rev. T. T. Lewis lived — the geologist who Murchison acknowledged had materially assisted him in establishing the Silurian System. In the northern portion of the district the Aymestrey Limestone has been worked in Wassell Wood and in ' The Old Road,' near Leintwardine, and near 'The Briery.' At the latter place there is seen in the quarry, in addition to an interesting fault, an example of what is called ' pene-contemporaneous erosion ' — the top portion of the Aymestrey Limestone seems to have under- gone a certain amount of erosion almost as soon as it had been formed. This phenomenon was first described by R. Lightbody.^' In the banks of the Teme between Downton and Downton Castle Bridge the complete succession of the Silurian Beds from the Aymestrey Limestone to Downton Castle Sandstones is magnificently displayed. The beds which come immediately below the Downton Castle Sandstones, the Upper White- clifFe or Ghonetes Flags form the core of the Downton Castle inlier, and are there succeeded by the Temeside Stage. The Upper Ludlow Stage is perhaps best known for its ' Bone-Bed,' which constitutes its highest bed. The ' Bone-Bed,' of which an excellent general account has been given by Dr. G. J. Hinde,^' is seen in the road leading down to Forge Bridge, near Downton Castle, and at other places in the neighbourhood ; while at the southern end of the district under con- sideration it is exposed at Bradnor Hill, near Kington.^" In the latter neighbourhood, near Quarry House, graptolites have been obtained from the Mocktree Shales.'^ The term ' Temeside Group ' has only recently been suggested. It is used in the same sense as the term ' Passage-Beds ' is employed by many " Salter, Ann. y Mag. Nat. Hist. (3rd Ser.), iv (1859), P- 45 ! Lee, Note-book of an Amateur Geologist (1881), p. 46. '* Quart. Joum. Geol. Soc. Ivi (1900), pp. 415-91. " Ibid. Ixii (1906), pp. 195-250. '* Ibid, xix (1863), pp. 368-71. ^ Proc. Geol. Assoc, xviii (1904), pp. 443-6. '° Quart. Joum. Geol. Soc. xii (1856), p. 94. " Proc. Geol. Assoc, xviii (1904), p. 487. See Murchison, Silurian System ; Siluria ; Quart. Joum. Geol. Soc. ix (1853), p. 16 ; ibid, xiii (1857), p. 290; Marston, Geol. Mag. vii (1869), p. 253 ; J. Harley, Quart. Joum. Geol. Soc. xvii (1861), p. 542 ; ibid. Rev. P. B. Brodie, ibid, xxv (1869), p. 236. 1 1
