VERTEBRATA 



INVERTEBRATA. 



Distribution of Animals in Time. (p. 420.) 

 Vertebrata. — i, Ganoid Fishes; 2, Telioil Fishes; 3, Batrachians ; 4, 



Reptiles; 5, Birds; 6, Mammals. 



Invertebrata.— \, Trilobites, etc. ; 2, Worms ; 3, Bivalve and Univalve 



Shellfishes; 4, Nautiloid Shellfishes ; 5, Cuttlefishes; 6, Brachiopods. 

 It will be noticed that Nos. 2 and 5 in the first table, and 3 and 5 in the 



second, follow a different order of curve from the others, indicating their 



exceptional culmination in modern times. 



