lithsonian Report, 1 91 5.- Walcott. 



Plate 10. 



SlDNEYlA INEXPECTANS WaLCOTT. 



The king of the animal world 15,000,000 years ago; discovered by Mr. Walcott. The spiny claws' 

 of the Middle Cambrian crustacean (Si'dnctjia inexpedans Walcott) are shown as a light patch iu 

 the center of Plate 9. From Burgess Pass shale, Field, British Columbia. 



