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limestone and shale, 150 ft. The Woolhope beds consist mainly of shales which are generally calcareous and pass frequently into irregular nodular and lenticular limestone. In the See also:

MALVERN

Malvern Hills there is much shale at the See also:

BASE

base, and in places the limestone may be absent. These beds are best See also:

DEVELOPED

developed in See also:

HEREFORDSHIRE

Herefordshire; they appear also at May See also:

Hill in See also:

GLOUCESTERSHIRE

Gloucestershire and in See also:

RADNORSHIRE (Sir Faesyfed)

Radnorshire. See also:

COMMON

Common fossils are Phacops caudatus, Encrinurus punctatus, Orthis calligramma, Atrypa reticularis, Orthoceras annulatum. The Wenlock Shales are See also:

PALE (through Fr. pal, from Lat. palms, a stake, for paglus, from the stem pag- of pangere, to fix; " pole " is from the same original source)

pale or dark-See also:

grey shales which extend through See also:

COALBROOKDALE

Coalbrookdale in See also:

SHROPSHIRE (SALOP)

Shropshire, through Radnorshire into See also:

CARMARTHENSHIRE

Carmarthenshire. They appear again southward in the Silurian patches in Gloucestershire, Herefordshire and See also:

MONMOUTHSHIRE

Monmouthshire. They thicken from the See also:

south northward. The fossils are on the whole closely similar to those in the limestones above with the natural difference that See also:

CORALS (KoRAis), ADAMANTIOS [in French, DIAMANT CORAY] (1748–1833)

corals are comparatively rare in the shales, while See also:

GRAPTOLITES

graptolites are abundant. Six graptolite zones have been recognized by See also:

MISS

Miss G. L.

Elles in this formation. The Wenlock limestone occurs either as a series of thin limestones with thin shales or as thick massive beds; it is sometimes hard and crystalline and sometimes soft, earthy or concretionary. It is typically developed in Wenlock Edge, where it forms a striking feature for some 20 m. It appears very well exposed in a See also:

sharp anticline at Dudley, whence it is sometimes called the " Dudley limestone "; it occurs also at Aymestry, See also:

Ludlow, Woolhope, May Hill, See also:

Usk and Malvern. The fossils include corals in great variety (Halysites caienularis, Favosites aspera, Heliolites interstinctus), crinoids (Crotalocrinus, Marsupiocrinus, Periechocrinus), often very beautiful specimens, and See also:

TRILOBITES

trilobites (Calymene Blumenbachii, the " Dudley See also:

LOCUST

locust," Phacops caudatus, Illaenus (Bumbastes)barriensis, Homolonotus delphinocephalus). Merostomatous crustaceans make their first See also:

APPEARANCE (from Lat. apparere, to appear)

appearance here(Eurypterus punctatus, Hemias pis horridus). Brachiopods are abundant (Atrypa reticularis, Spirifer plicatilis, Rhynchonella cuneata, Orthis, Leptaena, Pentamerus) ; lamellibranchs include the genera Avicula, Cardiola, Grammysia; Murchisonia, See also:

BELLEROPHON, or BELLEROPHONTES

Bellerophon, Omphalotrochus are common gasteropod genera. Conularia Sowerbyi is by no means rare, and there are several common cephalopod genera (Orthoceras, Phragmoceras, Trochoceras). The greater See also:

PART

part of the known Silurian See also:

FAUNA

fauna of Britain comes from Wenlock rocks; J. See also:

Davidson and G. Maw obtained no fewer than 25,000 specimens of brachiopods from 7 tons of the shale. Not only are there many different genera and See also:

SPECIES

species but individually certain forms are very numerous.

The three See also:

PRINCIPAL

principal zonal graptolites are, from above downwards: Monograptus testis, Cyrtograptus Linnarssoni, Cyrtograptus Murchisoni. When traced northward into Denbighshire and Merionethshire the rocks See also:

CHANGE (derived through the Fr. from the Late Lat. cambium, cambiare, to barter; the ultimate derivation is probably from the root which appears in the Gr. «a urmu', to bend)

change their See also:

CHARACTER (Gr. xapareri7p, from xap&crew, to scratch)

character and become more slaty or arenaceous; they are represented in this area by the " Moel Ferna Slates," the " See also:

PEN (Lat. penna, a feather, pen)

Pen-y-glog Grit," and " Pen-y-glog Slates," all of which belong to the See also:

LOWER

lower part of a great series (3000 ft.) of slates and grits known as the " Denbighshire Grits." Similar deposits occur on this See also:

HORIZON (Gr. 6pfTwv, dividing)

horizon still farther See also:

north, in the See also:

Lake See also:

DISTRICT

district, where the Wenlock rocks are represented by the " Brathay Flags " (lower part of the Coniston Flags series), and in See also:

SOUTHERN

southern See also:

Scotland, where their See also:

PLACE (through Fr. from Lat. platea, street; Gr. IrAar6s, wide)

place is taken by the variable " Riccarton beds " of See also:

KIRKCUDBRIGHT (pron. Ker-k4-bri)

Kirkcudbright See also:

SHORE

Shore, See also:

DUMFRIES (Gaelic, " the fort in the copse ")

Dumfries-See also:

SHIRE

shire, Riccarton and the Cheviots; by greywackes and shales in See also:

LANARKSHIRE

Lanarkshire; by mudstones, shales and grits in the Pentland Hills, and in the See also:

GIRVAN

Girvan area by the " See also:

Blair " and " Straiton beds." In See also:

Ireland the " Ferriters See also:

COVE

Cove beds," a thick series of shales, slates and sandstones with lavas and tuffs in the See also:

DINGLE

Dingle promontory; the" Mweelrea beds " and others in See also:

TIPPERARY

Tipperary and See also:

Mayo are of Wenlock See also:

AGE (Fr. age, through late Lat. aetaticum, from aetas)

age. Lime and flagstones are the most important economic products of the See also:

BRITISH

British Wenlock rocks. See the See also:

ARTICLE (from Lat. articulus, a joint)

article SILURIAN, and for See also:

RECENT

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WENNERBERG, GUNNAR (1817-1901)