32 



ANIMALS OF THE PAST 



REFERENCES 



The early fishes make hut little show in a museum, 

 both on account of their small size and the conditions 

 under which they have been preserved. The Museum of 

 Comparative Zoology has a large collection of these 

 ancient vertebrates, and there is a considerable number of 

 fine teeth and spines of Carboniferous sharks in the 

 United States National Museum. 



Hugh Miller''s '■'■The Old Red Saiidstone'''' contains 

 some charming descriptions of his discoveries of Pterich- 

 thys and related forms, and this book will ever ?-emain a 

 classic. 



Fig. 5. — Pterichthys, the Wing Fish. 



