LESSER AMERICAN FLYING SQUIRREL, 187 
animals alone, or extended to embrace the tropical 
species also. 
The Flying Squirrels were but little known to the 
earlier naturalists. Even down to the time of Linneus 
no clear distinction was made between those of America 
and the Polatouche of Siberia and northern Europe. 
It was Pallas who first pointed out with precision the 
actual differences between the latter and the more com- 
mon of the American species, which had been figured 
by Buffon under the Polish name in the erroneous idea 
that it was really the Polatouche. A third species was 
indicated by Forster in a brief notice of a collection 
made in Hudson’s Bay, published in the Philosophical 
Transactions. This has since been more fully charac- 
terized by Dr. Richardson, who, however, appears to be 
by no means satisfied of the correctness of its separation 
from the species found in the north of the Old Conti- 
nent. The same distinguished traveller had himself 
added a fourth to the list from the valleys of the Rocky 
Mountains; but he has subsequently reduced it to the 
rank of a variety only, and offers a guarded opinion 
that both it and the last may, without much violence, 
be united to the Polatouche. In that case the Flying 
Squirrels of the temperate zone would all be still refer- 
able to the two species originally established by Pallas. 
They closely agree in general form with the true Squir- 
rels; but are of smaller size, have rounder heads, and 
larger and more prominent eyes. 
The Lesser Flying Squirrel is little more than half 
as large as the more northern species, from which it 
also differs in many particulars of form, colouring, and 
habits. Its tail is longer in proportion, measuring 
three-fourths of the length of the head and body; and 
its head is somewhat more produced in front. On its 
upper surface the animal is of a bright mouse-colour, 
