LETTER OF TRANSMITTAL. Vll 



malian group brought together by the author iu these two volumes is most 

 extraordinary, and will probably never be surpassed. 



The plates which illustrate this volume were engraved by Thomas Sin- 

 clair & Son, of Philadelphia, and the figures were drawn on stone from the 

 specimens themselves, under the immediate supervision of Professor Cope. 



At the close of the fiscal year ending June 30, 1882, at my request, 

 the Secretary of the Interior placed the printing of the uncompleted vol- 

 umes of the quarto series in the care of Maj. J. W. Powell, the Director of 

 the United States Geological Survey, and I desire him to accept my cordial 

 thanks for his very kind attention and for many personal courtesies. 

 Very respectfully, your obedient servant, 



F. V. HAYDEN, 

 United States Geological Survey of the Territories. 

 The Hon. the Secretary of the I^TERIOR, 



Washington, D. C. 



