198 INDEX 



Extinction, sometimes evolution, 175, 176 

 of Titanotheres, 176 



Feathers, imprints of, 55, 109, 111 

 Fishes, abundance of, 15 



armored, 14, 15, 17 



collections of, 21 



killed by cold, 180, 181 



killed by volcanoes, 181 

 Fish-crows, killed by cold, 181 

 Flesh does not petrify, 6 

 Flight, 51, 52,* 53, 63-68, 73-79, 127, 128 

 Flightless birds, absent from Tasmania, 128 



present distribution, 128, 129 



relation between flightlessness and size, 129 

 Flying Reptiles, 69-79 

 Folds and frills, 107 

 Footprints, collections of, 31 



books on, 31 



See also under Tracks 

 Fossil birds, rarity of, 62 

 Fossil man, 8 



Fossilization a slow process, 6 

 Fossils, conditions under which they are formed, 3-6 



collecting, 97-100 



definition of, 1 



deformation of, 9, 10 



impressions, 2 



not necessarily petrifactions, 2 



preparation of, 100-102 



why they are not more common, 3, 9, 10 

 Fowls, muscles of, 57-59 

 Frill of Triceratops, 89 

 Fur-seals killed by ice-floes, 183 



