TO 
SIR RODERICK IMPEY MURCHISON, 
D.C.L., LL.D., E.R.S., 
DIRECTOR OF THE GEOLOGICAL SURVEY, 
ETC., ETC., ETC., 
WHOSE PRE-EMINENCE IN SCIENCE HAS ALWAYS 
BEEN COUPLED WITH A GENEROUS ENCOURAGEMENT OF THE 
LABROUKS OF OTHERS, 
This Whork ig Dedicated 
WITH FEELINGS OF HIGH REGARD AND ESTEEM 
BY 
THE AUTHOR. 
