SCIURUS. 131 
Of the geographical distribution of the various races we can only judge from the 
comparatively few specimens of which the exact localities have been noted. The hypo- 
pyrrhus phase appears to be the most northern, the col/iei to prevail principally along 
the Pacific slopes, and the dorsalis to be the most southern. ach, however, appears 
to be found along with others in some part. Thus, I have seen specimens of the hypo- 
pyrrhus type from Mexico, Honduras, and Guatemala, of rigidus from Guatemala, 
Nicaragua, and Costa Rica, of dorsalis from Nicaragua, Costa Rica, and Panama, 
and of collici from the west coast of Mexico and Guatemala, Nicaragua, and Costa 
Rica. The only localities which I know for the melanius phase are Nicaragua and 
Panama. 
Herr J. von Fischer has described the habits of a pair of this species in captivity, 
under the name of S. rigidus. He found them to be strictly diurnal animals, and to be 
fond of lying stretched on a branch in the full sunshine. On the ground their move- 
ments were much like those of the common European Squirrel, but they were always 
most unwilling to leave the branches. ‘They frequently assumed a peculiar position 
when feeding ; holding on to a branch by their hind feet, they would hang head down- 
wards and devour the food which they held between their fore paws?°. Several 
examples of the dorsalis and colliwi varieties have been exhibited of late years at the 
Zoological Society's Gardens, under the name of Sciurus dorsalis. 
Our Plate is drawn from the typical specimens of the melanius form in the British 
Museum. 
6. Sciurus variabilis. 
Sciurus variabilis, Is. Geoffroy, Mag. de Zool. 1832, pl. iv. (descr. orig.)’; Allen, Mon. N.-Am. 
Rodent. p. 7687; Bull. U.S. Geol. Surv. iv. p. 884°; Alston, P. Z.S. 1878, p. 665°. 
Sciurus gerrardi, Gray, P.Z,S. 1861, p. 92, pl. xvi. (descr. orig.)’; Allen, Mon. N.-Am. Rodent. 
p. 766°. 
Hab. Panama, Obispo (Hassler Exp., Mus. Coll. Harv.®), Caimito (Boucard, Mus. Paris.), 
Darien (Maack, Mus. Coll. Harv.*).—Souta America, to Bolivia and Peru *. 
In thé paper quoted above* I endeavoured to show that the Squirrels generally 
known by the various names of S. variabilis, S. langsdorffi, S. tricolor, S. gerrardi, and 
some others are merely phases of one widely distributed and extremely variable species. 
Mr. Allen, in his Monograph, had arrived at much the same conclusion, but kept the 
last-named distinct on account of its smaller size and shorter ears; but on examination 
of a sufficient series, I was unable to find any constancy in the proportions of the ears, 
while the difference in size totally disappeared, as shown by the following series of 
measurements :—9°50, 9°75, 10-00, 10°25, 10°75, 11, 11-50, 11°75, 12:00, 12°75, 13-00. 
The smaller specimens (S. variabilis, S. gerrardi, &c.) appear to prevail towards the 
north: but this is not constant; for a Santa-Martha example measures over 12 inches, 
S2 
