224 Bulletin American Museum of Natural History.  [Vol. XXXIV, 
Skull (4 specimens, same as above), total length, 52.9 (51.6-54.3); zygo- 
matic breadth, 31.2 (31-32); interorbital breadth, 16.9 (16-18); breadth 
of braincase, 23.7 (23.38-25); length of nasals, 16.6 (15-18); diastema, 
13.3 (13-14); maxillary toothrow, 8.8 (8.4-9). Three specimens from 
Panama Largo (near Bogota) give similar cranial and external measure- 
ments and agree in coloration with the Fusugasuga series. 
Specimens examined, 23.— Colombia: Bogota, 2, type and 1 specimen 
from Macanal, “near Bogota” (Br. Mus.); Fusugasugé (alt. 6000 ft.), 7 
(Am. Mus.); Panama Largo, 3 (Am. Mus.); Monte Redundo, 1 (Am. Mus.); 
Quitame, 4 (Am. Mus.); Anolaima, 6 (Am. Mus.)! 
Remarks.— Mesosciurus hoffmanni hyporrhodus is similar to typical 
hoffmanna in general coloration, but with a larger skull. The type has the 
axille marked with white (not mentioned in the description), as sometimes 
happens in true hof'manni. My notes on the type state: “Less dark and 
more fulvous above than average hoffmanni; similar to deep rufous-bellied 
hoffmanni below, and tail similar to average hoffmanni.’’ Gray’s descrip- 
tion emphasizes “the softness and length of hair and hairy ears,” but these 
are largely seasonal features. 
The specimens of this form recorded above are all from localities near 
Bogota, at altitudes of 6000 to 8000 feet. The Quitame specimens are 
winter (February) specimens, in very full coat, the pelage being thick and 
soit and the ears more hairy than in summer specimens, with the tufts of 
soft fulvous fur at the base of the ears well developed. These specimens 
indicate that Gray’s type was a winter specimen. 
Specimens of the hoffmanni group taken at different localities in the Co- 
lombian Andes show that the fluffy fulvous tufts at the posterior base 
of the ears are largely a seasonal feature, being conspicuously present in 
specimens taken in February, March and April, and practically absent or 
obsolete in August, September, October and November specimens. Simi- 
lar tufts are well known to be a seasonal feature in many species of arboreal 
squirrels. 
G. hoffmanni hyporrhodus is slightly larger than either true hoffmanni 
or griseogena, but it makes a distinct approach to the latter in coloration, 
especially through the increased amount of black at the tip of the tail, as 
compared with hoffmanni. Some of the specimens from the vicinity of 
Bogota are, in fact, not easy to distinguish from gresergena without recourse 
to the labels. For the present, however, it seems better to recognize the 
two groups as specifically distinct. 
1 Probably most, if not all, of the following 11 specimens from near Bogota, formerly 
examined in the British Museum but not now available for reéxamination, are referable to 
hyporrhodus: Plains near Bogota, 2; El Cofre, 2; La Palma, 2; Munzo Mines, 4; Quebrada 
de Murone,1. All were collected by G. O. Childs, probably at or near his estate near Bogota. 
