Fro, 4. 



Restoration (by G, F. Matthew) of a TrilobJte {Pttmdoxides) from the 

 Lower Cambrian, as an evidence of the existence of crustacean ani- 

 mals of high type and great complexity in this early age. If such 

 animals were evolved from Protozoa by slow and gradual changes, the 

 time required would be greater than that which iaterveneil fae^een 

 the Gunbrian period and the present time. 



10' 



113 



