SUBCLASS I 



TRILOBITA 



729 



Table showing Vertical Range of Trilobites 



[The foregoing chapter on Trilobites has been revised by Dr. Percy E. Raymond, of the 

 Museum of Comparative Zoology at Cambridge, Mass. Some notes on Cambrian genera, 

 together with two or three figures illustrating the same, have been contributed by Dr. C. D. 

 Walcott. — Editor.] 



