V S - 
UNITED STATES DEPARTMENT OF AGRICULTURE 
BUREAU OF BIOLOGICAL SURVEY 
WASHINGTON, D. C. 
ADDRESS REPLY TO 
chief, bureau of biological survey, September 9, 1920# 
AND REFER TO 
BI-S 
Argentina 
Dr. Alex Wetmore, 
c/o Consul General of the United States, 
Buenos Aires, Argentina. 
Dear Dr. Wetmore: 
Your letter of July 29 from las Palmas, Chaco, has 
just arrived, and we are very glad, indeed, to hear from 
you again. You appear to have located a very favorable place 
for work, and I shall look forward with the greatest interest 
to seeing your first shipment. 
I am glad to know the meaning of the word "Chaco.” I 
was under the impression that it probably meant "open plains 
country." 
Your observations on the method of feeding of large 
species of Icteridae is very interesting in connection with 
your investigations of the structure of the angle of the lower 
jaw and the reason for its posterior prolongation. 
> 1 # 
Several genera of small opossum are likely to be met 
with, and anything in that line we shall be very glad to have. 
Secure representatives of as many small mammals as possible in 
each locality. 
We are writing to the Bureau of Plant Industry to be on 
the lookout for the orange cuttings, which may prove to be a 
valuable introduction. 
In measuring small mammals please take the two dimensions 
of the hind foot, one inclusive and the other exclusive of longest 
claw. Mr. Oldfield Thomas of the British Museum has requested 
that in collecting mammals in South America we take measurements 
excluding thec|?aw, which will then be comparable with most of the 
material now in the British Museum, and I think that it would be 
wise to adopt his suggestion. 
