IV 



NOTE. 



At the tiuie wIr'U tlit- wcnk was tunitd over to the Director oi' the 

 Geological Survey an important portion of the manuscript was yet unpra- 

 pared ; l)ut, throui^h tlie energy of Professor Cope, the volume has been 

 raj)idlv brought to eomjjletion. Tlie work coustitutcs a vahiable oontrilm- 

 tioii to |iak-()iitology, and is a iiiniminent to the labor and genius of the 

 authoi- and to the administrative talent of Di' llavden. 



1 lie yet unpublished volumes will be pushed to completion at an 

 earlv day. 



Director U. S. Geological Survey. 



Washington, September II, 1883. 



