peface. xiii 



mcnt and revision of the manuscript ; and in seeing through the 

 press its latter portion, at considerable inconvenience to himself. 



I cannot close this, already somewhat lengthy preface, without 

 expressing my obligations to the numerous gentlemen throughout 

 the State, by whose kindness and intelligent assistance my labors 

 in the field have been essentially lightened, and the work of the 

 Survey materially promoted. EUG. W. HILGARD. 



Oxford, August, 1860. 



