1. Columnar Trap, New Holland. (_Dana._) 2. The four divisions of rocks, and their relative positions. _A_, Volcanic Rocks. _B_, Granite. 1, 2, 3, 4, Granite of different ages. _C_, Metamorphic Rocks. _D_, Fossiliferous Rocks. (_Lyell._) 3. Granite veins in slate, Cape of Good Hope. (_Hall._) 4. Granite veins traversing granite. (_Hitchcock._) 5. Extinct volcanoes of Auvergne. (_Scrope._) 6. Lava of different ages, Auvergne. (_Lyell._) 7. Strata folded and compressed by upheaval of granite. 8. Favosites Gothlandica. 9. Catenipora escharoides. (Chain coral.) 10. Caryocrinus ornatus. (_Hall._) { Leptæna alternate. Orthis testudinaria. } 11. { }(_Hall._) { Delthyris Niagarensis. } 12. Section of a chambered shell, showing the chambers and the siphuncle. 13. Orthoceras. 14. Curved Cephalopoda, _a_, Ammonite; _b_, Crioceras; _c_, Scaphite; _d_, Ancyloceras; _e_, Hamite; _f_, Baculite; _g_, Turrilite. (_Agassiz and Gould._) 15. Trilobite. 16. Cephalaspis Lyellii. (_Agassiz._) 17. Pterichthys oblongus. (_Agassiz._) 18. Fault in the coal formation, _a a_, layers of coal, _b b_, surface and soil. 19. Stigmaria ficoides; Newcastle. (_Lindley and Hutton._) 20. Trunk of sigillaria. (_Trimmer._) 21. Bark of sigillaria. (Natural size.) 22. Sphenopteris crenata. (_Lindley._) 23. Pachypteris lanceolata. (_Brongn._) 24. Sigillaria levigata. (_Brongn._) 25. Lepidodendron Sternbergii, Bohemia. (_Sternberg._) 26. Calamite. 27. Heterocercal fish. Homocercal fish. 28. Impressions of Raindrops, Wethersfield, Conn. (_Hitchcock._) 29. _b_, Bird tracks in the Conn. River Sandstone, _a_, Consecutive tracks; _c_, Track of Cheirotherium (probably a reptile), Penn. and Germany. 30. Section in the Isle of Portland. (_Buckland._) 31. Apiocrinites rotundus, Bradford, Eng. (_Miller._) 32. Gryphea incurva. 33. _a_, Outline of Ichthyosaurus; _b_, Plesiosaurus. 34. Pterodactyle. 35. _a_, Diploctenium cordatum; _b_, Marsupites; _c_, Salenia; _d_, Galerites; _e_, Micraster cor-anguinum. (_Agassiz & Gould._) 36. _b_, Belemnite. _a_, Restored outline of the animal to which it belonged. 37. Cerithium intermedium. 38. Murex alveolatus. 39. Conus concinnus. 40. Nummulite. 41. Outline of paleotherium. 42. Outline of anoplotherium. 43. Skeleton of the mastodon. 44. Univalve with entire mouth. 45. Univalve with notched mouth. 46. Unimuscular bivalve. 47. Bimuscular bivalve. 48. Parallel planes of cleavage intersecting curved strata. (_Sedgwick._) 49. _a b_, A vein of segregation; _c d_, A dike. 50. Faults and denuded strata. 51. Vertical conglomerate. (_Lyell._) 52. Inclined strata in Dorsetshire, England. (_Buckland._) 53. Dip of strata.