Page:The South Staffordshire Coalfield - Joseph Beete Jukes - 1859.djvu/131

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SILURIAN ROCKS.
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It will be seen that this is a Wenlock Limestone list, and there are, indeed, few localities where the Woolhope band possesses any great distinctive character to separate it from the Wenlock. At Presteign. Radnorshire, it has, perhaps, the most peculiar facies. (See "Siluria," 2nd ed., p. 118.)

3. A few localities in the Weenlock Shale, such as the "Five Lanes" near Walsall, and the Bell in the same neighbourhood, are full of the characteristic fossils; a few are not known in the beds below. There are the ordinary brachiopod shells above mentioned, with Strophomena imbrex of Davidson, and Obolus transversus; the last is most abundant. This curious shell occurs also in the May Hill sandstone (but not of this district). Pentamerus galeatus and Athyris tumida, two or three species of Pterinea, especially the Pt. (?) planulata, which grows to a large size. Cardiola striata, a Lower Ludlow shell. Acroculia Haliotis, Bellerophon, Phragmoceras pyriforme, and a smooth Orthoceras, Encrinurus punctatus, and Phacops caudatus, are the common trilobites. Ptychophyllum patellatum and Heliolites inordinatus are conspicuous corals in the shale.

4. The Wenlock Limestone (divided into two bands by a thick layer of shale, as above described) contains all the fossils above noted, with the addition of a host of others. Indeed, the quarries of Dudley are the most famous in the world for Upper Silurian organisms. Shells, corals, encrinites of very numerous genera and species, and trilobites, are all in a state of perfection such as no other locality in Britain exhibits. The well known collections of Messrs. Gray and Fletcher at Dudley, and the cabinets of nearly every public museum in Britain or elsewhere, are evidences of the great labour expended in collecting and developing these beautiful remains. A mere list of them would include nearly all the Upper Silurian forms in Britain. It will be necessary, therefore, to give only the more striking forms. The asterisks denote the comparative abundance of the species.

Among the trilobites the following are conspicuous:—

Calymene Blumenbachi *****, the Dudley trilobite or Dudley locust, an universal Silurian fossil.

Homalonotus delphinocephalus, a fine species, more common in the Woolhope limestone.

Lichas Anglicus ****, and L. Barrandii, with three other species.

Acidaspis Brightii ***, A. quinquespinosa ***. A. crenata, the large A. Barrandii, ***, &c.

Staurocephalus Murchisoni, found also in Lower Silurian rocks and in Bohemia.

Cheirurus bimucronatus *, and Spherexochus mirus ** (this last ranges to America).

Encrinurus punctatus ******, and E. variolaris ******, the strawberry-headed trilobites of Dudley, among the commonest of all the Dudley species.

Phacops Downingia ****, P. Stokesii, and P. caudatus **, all of them very common species.

Proetus latifrons, M'Coy, with another species, and the beautiful little Cyphaspis megalops ****, in which last, as well as in several other species above mentioned, the Dudley specimens show more or less clearly both sexes—the males narrower and with longer spines than the females.

Then of other classes, the Annelida for instance, we have Cornulites serpularius and Tentaculites ornatus in myriads. Dudley is especially rich in corals and Crinoidea. Of the last, multitudinous species are in