xvi LIST OF ILLUSTRATIONS. 
Page 
Fossils (45). Lower Silurian Trilobites from the ' Primordial Zone ' of North 
Wales 203 
Fossils (46). Trilobites &c. typical of the Lower Silurian Eocks \ 204 
Fossils (47). Trinucleus concentricus, distorted by slaty cleavage 205 
Fossils (48). Lower Silurian Trilobites 206 
Fossils (49). Llandovery Brachiopods 210 
Fossils (50). Upper Silurian Polyzoa 216 
Fossils (51). Wenlock Polyzoon (Ptilodictya scalpellum) 217 
Fossils (52). Section of Stromatopora striatella 218 
Fossils (53). Corals of the Upper Silurian Eocks 219 
Fossils (54). Cup -Corals of the Wenlock Limestone . 220 
Fossils (55). Cystidea of the Wenlock Limestone 222 
Fossils (56). Crinoidea of the Wenlock Limestone 224 
Fossils (57). Upper Silurian Starfishes 225 
Fossils (58). Upper Silurian Brachiopoda 226 
Fossils (59). Upper Silurian Brachiopoda 227 
Fossils (60). Upper Silurian Lamellibranchiata 228 
Fossils (61). Upper Silurian Lamellibranchiata 229 
Fossils (62). Upper Silurian Cephalopoda 232 
Fossils (63). An Upper Ludlow Cephalopod (Ascoceras Barrandii) ..... 233 
Fossils (64). Upper Silurian Crustacea 234 
Fossils (65). Wenlock Limestone Trilobites 235 
Fossils (66). An Upper Silurian Crustacean (Ceratiocaris) 236 
Fossils (67). Pterygotus and Eurypterus, from the Tilestones of Kington . . 239 
Fossils (68). Fishes from the Ludlow Eock and Passage-beds 240 
Section . . From the top of the Silurian Eocks, on the N.W., across the whole 
area of the Old Eed Sandstone, to the bottom beds of the South- 
Welsh Coal-field, on the S.E 244 
Fossils (69). Crustacean from the Old Eed of Brecknockshire 246 
Section . . Across the south end of the Pentland Hills 249 
Section . . Across the Old Eed of Forfarshire 251 
Section , . General Section of the Old Eed Series (Caithness and Orkney Islands) 255 
Sketch . . View of the Old Eed Succession, from near the Ord of Caithness . 257 
Fossils (70). Old Eed Sandstone Fishes (Pterichthys and Coccosteus) .... 262 
Fossils (71). Old Eed Ganoid Fish (Dipterus macrolepidotus) 263 
Fossils (72). Cranium of an Orkney Fish (Diplopterus borealis) . ■ 264 
Fossils (73). Old Eed Sandstone Plants (Caithness) 269 
Section . . Across North Devon 272 
Fossils (74). Of the Central or Great Devonian Limestones 278 
Fossils (75). Of the Upper Devonian 279 
Section . . Succession of the Eocks in the South-west of Ireland .... 281 
Fossils (76). Fossil Plant from the Yellow Sandstone of Ireland 283 
Sketch . . Ideal View of the Vegetation of the Carboniferous Era 286 
Section . . General Eelations of the Carboniferous Eocks in the Central and 
Southern parts of England 288 
Sketch . . Cliffs of Carboniferous Limestone near Stackpole 289 
Sketch . . Stackpole Eock 289 
Section . . Slash of Culm, in Pembrokeshire 290 
Section . . Across the Cornbrook Coal-basin of the Clee Hills 290 
Fossils (77). Prestwichia rotundata, from Coalbrook Dale *298 
Fossils (78). Coral of the Mountain-limestone (Lithostrotion floriforme) . . . 299 
Fossils (79). Some Fossils of the Carboniferous Limestone 299 
Fossils (80). Insect and Shells of the Coal 300 
Fossils (81). Fern from the Coal of Coalbrook Dale 300 
Fossils (82). From the Uppermost Limestone of the Coal-measures 301 
