INTRODUCTION. 1)1 



be represented by — a tooth, a vertebra, or perchance a portion of 

 a femur or a humerus. Similar fragments will represent our col- 

 lections of Pachyderms, Ruminants and Cetaceans. Of Birds we 

 shall have nothing ; of the great Land-Saurians nothing. The 40 or 50 

 genera and more than 100 species of Marine Lizards will be represented 

 by the paddle, or quite possibly by the entire skeleton of a young Ichthy- 

 osaurus. While among Fishes, we shall have several scores of specimens, 

 of which only half a dozen will be perfect. A similiar incom- 

 pleteness, though to a somewhat less extent, will appear among many 

 divisions of the Invertebrates. In a word, we may be able to show 

 labels for a very full series of Fossils throughout the entire 

 Zoological series, but the specimens themselves give the student a very 

 faint idea of the animals for which they stand. Once more ; there 

 will be no representation whatever of scores of the most interesting 

 forms which Geology has ever revealed. We have none of the Quad- 

 rumana ; none of the great Carnivores — such as Machairodus and 

 Hyasnodon ; none of the Rodents ; no Megatherium, Grlyptodon, or 

 other Edentates ; no Sivatherium, Dinotherium, Paleeotherium, Rhi- 

 noceros, Hippopotamus, Tapir or Toxodon ; not even any perfect skulls 

 with which to convey some exact idea of our own great Mastodons 

 and Mammoths ; no Marsupials, Cetaceans or Birds, no Iguanodon, 

 Megalosaurus, Labyrinthodon, Mosasaurus, Pliosaurus, Pterodactyle, 

 and many more gigantic Reptiles whose names are familiar to us all, 

 but of which, for the very reason we are noting, the majority of our 

 students' and not a few teachers (not professionally men of science,) 

 are strangers to any accurate idea. The same thing will be true 

 in many important forms of Invertebrates, — although the greatest 

 difficulty in this division will be that the state of the individual 

 specimens secured will be such that they represent the genus or the 

 species far more often than they will show the particular points by 

 which these are characterized. A series of type-specimens of Am- 

 monites, Crinoids, and Trilobites might be purchased, perhaps, for 

 $50.00, — at least the labels would show most important generic names, — 

 but $1,000. and a vast deal of labor would be a low price for perfect 

 specimens of these same forms. 



The author of these pages has had considerable experience of the 

 difficulties above mentioned, in his eiforts during the last six years 

 to give completeness to the Palaeontological Cabinet of the University 

 of Rochester. He has found that the only possible way to give this 

 collection its desired symmetry was by the introduction, in the classifi- 

 cation, of Plaster Copies of very many of these fossils, the originals 

 of which are either unique specimens or are so very rare that it is 



