LIST OF ILLUSTRATIONS. 
FRONTISPIECE. View in the North-western Highlands of Scotland (geologically 
coloured), showing how the Laurentian Kocks are there surmounted by Cambrian 
and Silurian Rocks. 
TABULAR DIAGRAM of the comparative development of the Silurian Rocks in 
different parts of Wales, by Mr. Talbot Aveline (see p. 142). 
GEOLOGICAL MAP of the Silurian Rocks and overlying Formations in Wales and 
the Border Counties ; with a General Section of the Rocks from Snowdon to Wen- 
lock Edge. (End of Volume.) 
WOODCUTS. 
Page 
Fossils (1) . Eozoon Canadense 13 
Section . . General Order of the Primeval Rocks 24 
Sketch . . The Longmynd 25 
Section . . From the Longmynd on the E.S.E. across the Stiper Stones to Shelve 
and Cornden on the W.N.W 26 
Fossils (2) . Burrows of Annelides allied to Arenicola, and Palseopyge Ramsayi . 28 
Fossils (3) . Oldhamia antiqua, from Carrick MacReilly, Ireland 30 
Sketch . . Pass of Llanberis from the Lower Lake 30 
Section . . Bedding and Slaty Cleavage ...» 32 
Sketch . . Contorted Crystalline Schists at the South Stack Lighthouse, Anglesea 35 
Section . . Showing the Relations of the Lower Silurian Rocks in the West of 
Shropshire 38 
Sketch . . Eastern face of the Stiper Stones 39 
Sketch . . Western face of the Stiper Stones 39 
Fossils (4) . Annelide-burrows in the Stiper Stones 40 
Section . . General Arrangement of Rocks between Cader Idris and the flank of 
Snowdon . , 41 
Section , . Conformable Passage from the Cambrian Rocks to the Lingula-flags 
at Barmouth 42 
Fossils (5) . From the Lingula-flags, North Wales 43 
Fossils (6) . From the Lingula-flags, North Wales 44 
Fossils (7) . From the Black Schists of the Malverns 45 
Fossils (8) . From the Upper part of the Lingula-flags, North Wales .... 46 
Fossils (9) . From the West side of the Stiper Stones 48 
Sketch . . Lower Silurian tract west of the Stiper Stones (Shelve, &c.) ... 49 
Fossils (10). From the Lower Llandeilo Rocks of North Wales 51 
Fossils (11). Characteristic Fossils of the Llandeilo Flags 51 
Section . . Lower Silurian Rocks in Abereiddy Bay 53 
Section . . Llandeilo Schists in Musclewick Bay . . 53 
Section . . At Llandewi Felfry, Pembrokeshire .54 
Sketch . . From Dynevor Park, Llandeilo, looking to the Hills above Golden 
Grove 54 
