32 ANIMALS OF THE PAST 
REFERENCES 
The early fishes make but 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 Zovlogy has a large collection of these 
ancient vertebrates, and there is a considerable number of 
Jine teeth and spines of Carboniferous sharks m_ the 
United States National Museum. 
Hugh Miller's “The Old Red Sandstone” contains 
some charming descriptions of his discoveries of Pterich- 
thys and related forms, and this book will ever remain a 
classic. | : 
Fig. 5.— Pterichthys, the Wing Fish. 
