HOLLAND AND PETERSON: OSTEOLOGY OF THE CHALICOTHEROIDEA. 197 
In conclusion I desire to express my appreciation of the knowledge and skill 
of my associate, Mr. O. A. Peterson, who recovered much of the material, and 
prepared it for study and description. The constant pressure of executive duties 
prevented me at times from applying myself to the work of preparing this mono- 
graph, and I have therefore, in order to bring it to conclusion, availed myself of 
Mr. Peterson’s services in partly preparing those sections of this paper, which 
relate to the appendicular skeleton, and to the skull and dentition. Mr. Peterson 
is justly entitled so far forth to be regarded as a joint author. The painstaking 
fidelity of Messrs. W. H. Utterback and Mr. 8. Agostini in the work of the labo- 
ratory deserves to be acknowledged. 
Mr. Sidney Prentice with great skill has prepared the drawings. The photo- 
graphs, which are reproduced, were made by Mr. A. 8. Coggeshall. 
Finally I cannot conclude these preliminary remarks without giving expression 
to the sentiments of gratitude which all the members of the paleontological staff 
of the Carnegie Museum, who have worked in this field, entertain toward Mr. 
James H. Cook, his most amiable wife, and his sons, who during the whole time 
during which we were engaged in exploiting the quarries, not only showed intelli- 
gent interest in our labors, but accorded to us the most delightful hospitality. 
Hearty thanks are also due to Mr. John A. Anderson of Harrison, Nebraska, who, 
refusing all compensation, kindly took charge for a number of winters of our 
stock and camping outfits, and who has under his hospitable roof from time to 
time entertained the gentlemen connected with the Museum who have been 
collecting in the region. Our thanks are also due to Mr. Octave Harris for kind 
permission during the summer of 1908 to occupy the buildings on his upper or 
“Castle Rock Ranch,” thus providing our party with the most comfortable quarters 
which they have probably ever possessed on a similar expedition. The genuine 
““Western hospitality’ shown by these gentlemen has endeared them all in memory 
to their scientific friends from the Carnegie Institute. 
