2 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 97 
The author expresses his thanks to the authorities of the American 
Museum of Natural History for the loan of specimens and permission 
to examine the type specimens in their charge; to the authorities of the 
Chicago Natural History Museum for the loan of specimens and _ per- 
mission to describe one of the squirrels in their collection; to Charles 
M. B. Cadwalader, director of the Academy of Natural Sciences of 
Philadelphia, for permission to examine the type of Notosciurus; to 
J. Kenneth Doutt, of the Carnegie Museum, for giving the writer un- 
conditional access to the specimens in his care with permission to report 
upon them; and to Hermano Nicéforo Maria, of the Instituto de La 
Salle, Bogota, for the gift of valuable specimens of squirrels that are 
now in the United States National Museum. Deep appreciation is 
expressed to the members of the staff of the British Museum (Natural 
History) and of the Muséum National d’Histoire Naturelle, Paris, for 
the freedom enjoyed by the author in examining the collections of 
mammals in their charge. 
In the lists of specimens, the following abbreviations are used: 
A.M.N.H.=American Museum of Natural History. 
B.M. = British Museum (Natural History). 
C.M. = Carnegie Museum, Pittsburgh. 
C.N.H.M.=Chicago Natural History Museum. 
M.C.Z. =Museum of Comparative Zoology, Harvard University. 
M.N.H.N.= Muséum National d’Histoire Naturelle, Paris. 
U.S.N.M. =United States National Museum. 
Most color terms mentioned in the descriptions are shown in Robert 
Ridgway’s ‘‘Color Standards and Color Nomenclature’’ (43 pp., 53 
pls., Washington, 1912). 
SCIURUS GRANATENSIS Humboldt 
The characters of the species may be said to be, roughly, those given 
for the “genus” Mesosciurus by Allen (1915, p. 212). Since the time 
of Allen’s monograph, his Mesosciurus has been synonymized with 
Guerlinguetus, and this, in turn, has generally been accorded subgeneric 
rank. Because of the strictly limited geographical scope of this work, 
the description of the species in the following pages is given largely in 
terms of the subspecies which occur in northern Colombia and north- 
western Venezuela (map, fig. 1). Wherever necessary for purposes 
of comparison, reference is made to the races of outlying areas. 
TAXONOMIC HISTORY OF THE MEDIUM-SIZED SQUIRRELS OF COLOMBIA 
The first name applied to a squirrel with a Colombian locality is 
Scirus flavus Linnaeus. It is described on page 64 of the tenth 
edition of the Systema Naturae as “luteus, apicibus pilorum albis. 
. . . Habitat in America.” On page 86 of the twelfth edition, Lin- 
naeus-added the habitat ‘““Cartagenae’”’ to the description. However, 
