Fig. 37. CAVE OF FINGAL, STAFFA. 



THE CRUST OF THE EA.RTH; 



OR, FIRST NOTIONS OF GEOLOGY. 

 CHAPTER II. 



46. General section of the terrestrial crust tabulated. 47. Approximate 

 thickness of strata. 48. Probable time necessary for their deposition. 

 49. Recapitulation of the physical history of the globe. 50. Depo- 

 sition of organic forms. 51. Alternate elevation and depression of the 

 crust. 52. The strata are botanical and zoological museums of past 

 creations. 53. The gradual increase of forms of life. 54. Creative 

 power has always operated on the same general plan. 55. But has 

 varied from period to period in details. 56. Animals created gradu- 

 ally ; the more perfect being the more recent. 57. Tabular view of 

 the progress of the animalisation of the earth. 58. Great increase 

 of vertebrates in the tertiary period No human fossil Man charac- 

 teristic of the present period. 59. Temporary existence of certain 

 extinct genera and species. 60. Geological use of characteristic genera 

 and species. 61. Examples Trilobites characteristic of the Silurian 

 strata. 62. Description of them. 63. Dr. Buckland's reflections on 

 them. 64. Species characteristic of the lias Ichthyosaurus. 65. 

 Characteristics of the Wealden Hylseosaurus Iguanoclon. 66. Cha- 

 racteristics of the chalk. 67. Ammonites, their distribution between 

 the Silurian and chalk. 68. Fossil cephalopodes Nautilus Damans. 

 69. Fossil gasteropodes Bigranulosa murchisonia Cyprsea elegans 

 Yoluta elongata Pterocera oceani. 



46. A GENEEAL idea of the series of stratified rocks, proceeding 

 LARDNER'S MUSEUM OP SCIENCE. E 49 



No. 134. 



