66

Shales are more argillaceous and less sandy and calcareous than the Upper-Ludlow rocks, and in the words of Murchison "they constitute, in fact, a great argillaceous mass, strictly entitled to the provincial name of 'mudstone.'" The beds immediately below the Aymestry Limestone are occasionally worked for flags, and are locally called "pendles." Separating these flags in some parts are the peculiar deposits of clay termed by the country-people "Walker's Earth" or Soap "-a kind of Fullers' Earth. The Aymestry Limestone is made up of more or less flaggy beds of a bluish-grey colour, frequently traversed by veins of calcite, and is much inferior in quality to the Wenlock Limestone. Murchison records that "its earthy character renders it, however, of very great value as a cement, particularly in subaqueous operations, and in ceiling and plastering, the mortar which is made of it setting rapidly under water." (Silurian System, p. 204). Conchidium Knighti is the characteristic fossil, and abounds in almost every quarry in the neighbourhood of the village of Aymestry-or " Aymestrey,' as it is now spelt. The Upper-Ludlow beds comprise thinbedded, pale-coloured, and somewhat micaceous sandstones, in some places highly argillaceous, in others equally calcareous. The top-bed is the well-known Ludlow Bone-Bed.

TEMESIDE STAGE.-This embraces those beds concerning which there was for many years doubt as to whether they should be classed with the Old Red or with the Silurian. Now they are by common consent regarded as Silurian. The Stage comprises sandstones (Downton-Castle Sandstones) in the lower portion, replete at certain horizons with fish and crustacean remains and Lingula minima; and shales, in which Eurypterid remains predominate, and through which Lingula cornea ranges, in the upper.

(ii.) LOCAL Details.

(A) LUDLOW-HUNTINGTON DISTRICT.-In the distribution of its rocks this district somewhat resembles that of Woolhope. The pyriform area that the beds occupy, however, is not anything like so symmetrical, neither do Old-Red rocks surround it. They occur on the south-eastern side and are faulted against the Silurians for a space on the north, but the western boundary of the district is a fault-a continuation of that which plays so important a part in the structure of the Church-Stretton district. Forces acting from easterly and southerly directions no doubt caused the domical disposition of the beds, while the proximity of a rigid mass, probably the Longmynds, prohibited greater symmetry being obtained. But even as it is the broad end of the pyriform area has been hollowed out into what Murchison called a valley of elevation," and through it meanders the River Teme.

MAY-HILL SANDSTONE.-Close to the great fault on the west is a small introduced patch of this rock overlying unconformally the Dictyonema-Shales. Except for this small introduced mass near Pedwardine, the Wigmore Valley is floored with the soft Wenlock Shales, which are obscured in many places by Superficial Deposits.

WENLOCK SHALES.-These are rarely seen, but Phacops longicaudatus has been obtained from an exposure in the bed of the Teme near Burrington."

WENLOCK LIMESTONE.-This limestone constitutes an illdefined ridge skirting the lowlands of the Wigmore Valley. It is exposed in two quarries at the foot of Elton Lane and in a roadcutting between Elton and Ludlow.75

LOWER LUDLOW SHALES.-The most important section in the Herefordshire portion of the Ludlow district is at Elton Lane. Between the brook and where the road bifurcates is a small exposure of shale crowded with brachiopods, corals, and trilobites; then up the lane to the left exposures in the Zones of Monograptus Nilssoni, M. scanicus, and M. tumescens; while the Aymestry Limestone, a deposit of M.-leintwardinensis date, crops out higher up and forms the capping to the hill. Returning, and taking the turning to the right, a similar succession of shale-beds is seen.76 The Zones of M. Nilssoni and M. scanicus are seen in the road from Elton to Ludlow, and that of M. tumescens, comprising hard flaggy beds, the local "Pendles," in a quarry on the hill-top near Gorsty Farm. A section of shales, possibly lower in the series than those seen in the preceding exposures, is obtained in the lane south of Stormer Hall, near Leintwardine, and it was here that the type-specimen of M. Salweyi, Hopkinson, was obtained." Near Leintwardine Church is an old quarry in the flaggy top-beds of the Lower Ludlow. This is the classic section which as early as 1857 had yielded no less than ten species of star-fish." Since then, as the Rev. J. D. La Touche has remarked, it is possible that many more species might be added. It was here that A. Marston worked with so much success, as the slabs in the Ludlow Museum, covered with Palecocoma Marstoni,. testify, and that J. E. Lee obtained the earliest known fish, Scaphaspis ludensis. Here also were procured Pterygotus arcuatus," Salter,

81

80

73 Q.J.G.S., xxxiii. (1877), p. 660.

74 Proc. Geol. Assoc. iii. (1873), p. 125.

75 Q.J.G.S., lvi. (1900), p. 425.

76 Id., p. 427.

77 Rep. Brit. Assoc., Bradford, p. 83.

78 See also Proc. Geol. Assoc., xviii. (1904), P. 491.

79 Ann. and Mag. Nat. Hist., 2 ser., xx. (1857), p. 321; see also H. Woodward, Q.J.G.S., xxi. (1865), p. 499.

80 Trans. Woolhope Nat. F.C, 1890 (1894), P. 36.

81 Salter, Ann. and Mag. Nat. Hist., 3 ser., iv. (1859), p. 45; Lee, "Note-book

of an Amateur Geologist" (1881), p. 46.

82 Mem. Geol. Surv., Monogr. 1 (1859), p. 95.

83

Eurypterus punctatus, Salter, Hemiaspis limuloides, H. Woodward,84 H. speratus 85 H. Woodw., and Necrogammarus Salweyi, H. Woodw.86 Near Kington the Lower Ludlow Shales are exposed in Bradnor Wood.

AYMESTRY LIMESTONE AND UPPER LUDLOW SHALES.-In the Ludlow district these beds have been exhaustively studied by Miss G. L. Elles and Miss I. L. Slater.87

89

88

The Aymestry Limestone is worked by the road-side in Wassell Wood to the north-west of Lugwardine, and in a large quarry near "The Briery." At the latter place the Mocktree Shales are faulted against the Aymestry Limestones, which is full of Conchidium Knighti, and the top-portion of the limestone seems to have been subjected to pene-contemporaneous erosion. This phenomenon, first described by Lightbody," has been studied in later years by the Woolhope Club" and Geologists' Association. In a quarry by the side of the lane called "The Old Road," near Leintwardine, of which a sketch made by Marston has been reproduced by Symonds," remains of Pterygoti are said to have been found in shales associated with limestones containing C. Knighti.

92

On the top of the hill near Mary-Knoll Farm, to the south-west of Ludlow, there are openings in the Aymestry Limestone, and the road thence to Ludlow passes over Mocktree Shales and Lower and Upper Whitecliffe-Flags. The finest section, however, in the district is that in the banks of the Teme between Downton and Downton-Castle Bridge. Here the complete succession from the Aymestry Limestone, which is worked at Bow Bridge, through the Mocktree Shales, Lower and Upper Whitecliffe-Flags, to the DowntonCastle Sandstones, is magnificently displayed. The Upper Whitecliffe- or Chonetes-Flags are exposed by the side of the main road north of Downton Castle, and similar beds form the core of the Downton inlier, being visible at several places near the river. The Ludlow Bone-Bed, for which this district is well known and of which an interesting general account has been published by Dr. G. J. Hinde," is seen in the side of the lane leading down to Forge Bridge, along the tract to Forge Rough, and again farther to the north-east close to the cottage by Old Millrace-weir.

83 Id., p. 99; see also Q.J.G.S., xxiv. (1868), p. 290.

84 Rep. Brit. Assoc., 1864, Bath; Q.J.G.S., xx. (1864), P. 490.

85 Monogr. Brit. Foss. Crustacea, Order Merostomata, Pal. Soc., p. 178.

86 Trans. Woolhope Nat. F.C., 1870 (1871). pp. 271-272; Huxley and Salter Mem. Geol. Surv. Monogr. 1 (1859), p. 25.

87 Q.J.G.S., lxii, (1906), Pp. 195-222.

88 Q.J.G.S., Ixii. (1906), p. 214.

89 Proc. Geol. Assoc., iii. (1873), p. 125

90 Q.J.G.S., xix. (1863), pp. 368-371.

91 Trans. Woolhope Nat. F.C., 1890 (1894), P. 27.

92 Proc. Geol. Assoc., xviii. (1904), P. 491.

93 In Dr. H. Woodward's Monograph, p. 94.

94 Proc. Geol. Assoc., xviii., pp. 443-446.