PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 
SMITHSONIAN INSTITUTION 
U. S. NATIONAL MUSEUM 
Vol. 97 Washington: 1947 No. 3208 
MAMMALS OF NORTHERN COLOMBIA 
PRELIMINARY REPORT NO. 1: SQUIRRELS (SCIURIDAE) 
By Puitie HersHKovitz 
In Tuts and succeeding accounts of the mammals collected by the 
author in northern Colombia during the first 2 years of his tenure of 
the Walter Rathbone Bacon Traveling Scholarship, those animals 
requiring special taxonomic treatment will be discussed. The final 
report on the collection will contain a complete and annotated list of 
the mammals, a full description of the region and the individual col- 
lecting stations, an account of the itinerary, and the general conclusions 
to be derived from a study of the classification, distribution, and ecology 
of the mammals of the region. Acknowledgment will be made to the 
institutions and the many individuals who enabled the author to pre- 
pare these accounts. 
During the course of the field work special attention was given to the 
collecting of sciurids. Two species of squirrels were found, and it is 
almost certain that more do not occur in the region. The first species, 
the pigmy squirrel, genus Microsciurus, is represented by two specimens 
from the Rio San Pedro, near Norosi, Bolivar Department. These 
are here assigned to Microsciurus alfari Allen, the oldest available 
specific name for the genus. tis unlikely that valid specific differences 
exist between any of the described forms. 
The second species found is represented by 225 specimens. [For this, 
the generally overlooked name of Sciurus granatensis Humboldt is ap- 
plicable. This highly variable species is shown to be the equivalent 
of most of (if not all) the “species” of the defunct ‘‘genus” Mesosciurus 
and liquidates the heretofore admitted genus, or subgenus, Noto- 
sciurus with its single species, rhoadsi. 
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