LIST OF ILLUSTRATIONS xi 



FIGURE PAGE 



60. Paleogeographic map of North America in the Silurian period . . . 109 



61. Sketch map showing the relations of land and water in Europe dur- 



ing Silurian time Ill 



62. Silurian and Devonian Corals 113 



63. Silurian Echinoderms 114 



64. Silurian Trilobites 115 



65. A Silurian Eurypterid, Eurypteris remipes, restored to show dorsal 



side 116 



66. A Silurian Scorpion, Paleophonus ciledonicus 117 



67. A bit of Silurian sea-bottom showing Crinoid, Bryozoan, Brachio- 



pod, and Trilobite remains 118 



68. Map showing surface distribution (areas of outcrops) of Devonian 



strata in North America 123 



69. Paleogeographic map of North America during early Devonian 



time 126 



70. Paleogeographic map of North America during Middle Denovian 



time 127 



71. Upper Devonian shales along the Genesee River in western New 



York 129 



72. Sketch map showing the general relations of land and water in 



Europe during the Devonian 131 



73. A Devonian Asterozoan, Paleister eucharis, on a Pelecypod shell. 134 



74. Devonian Brachiopods 135 



75. Devonian Pelecypods 135 



76. Devonian Gastropods 136 



77. A Devonian Goniatite, Manticoceras patersoni 136 



78. Devonian Trilobites 137 



79. A very simple Devonian Vertebrate, Palesopondylm gunni .... 137 



80. Devonian Ostracoderms 138 



81. A Paleozoic (early Mississippian) Selachian or Shark, Cladoselache 



fyleri 139 



82. Devonian Fishes 139 



83. Structure of a Ganoid tooth 140 



84. Types of Fish tails 141 



85. Map showing the surface distribution (areas of outcrops) of Missis- 



sippian and Pennsylvanian strata in North America 145 



86. Map showing the surface distribution (areas of outcrops) of Mis- 



sissippian strata in eastern North America 146 



87. Paleogeographic map of North America in Mississippian time . . . 149 



88. Generalized section in Iowa, showing how the Pennsylvanian sys- 



tem (C) rests unconformably upon the Mississippian (M) . . . 150 



89. Sketch map showing the relations of land and water in Europe 



during Mississippian (Lower Carboniferous) time 151 



90. Mississippian Cup-corals, Lonsdaleia canadense, forming a compact 



mass or colony 154 



91. A Mississippian Blastoid head, Pentrimites elongatus 155 



92. A Mississippian Crinoid head, Forbesiocrinus wortheni 155 



93. Map showing the surface distribution (areas of outcrops) of Penn- 



sylvanian rocks in eastern North America 159 



