MONTAGUA POLLEXIANA. 
65 
shorter than the superior, with the peduncle extending 
as far as the middle of the flagellum of the superior. 
The last joint of the peduncle of the inferior pair is 
rather longer than the preceding, and the flagellum is 
rather shorter than the last joint of the peduncle. The 
first pair of legs are slender, the fourth joint of which is 
but slightly produced anteriorly below, where it is tipped 
with long hairs ; the wrist is very long, and fringed upon 
the lower side with fine hairs ; the hand is much shorter, 
scarcely more than half the length of the wrist, it is 
also narrower ; it increases in width towards the palm, 
which is short and imperfectly defined. The finger is as 
long again as the palm, and nearly straight. The second 
pair of legs are longer and stronger than the first ; the 
hand is twice as long as broad, the upper and lower 
margins are imperfectly parallel, the form of the organ 
is therefore oblong-quadrate ; the palm is advanced, 
smooth, and fringed with a few solitary hairs; just 
within the inferior angle is a narrow deep cleft or 
notch, extending in depth to about one-third the length 
of the hand, giving to the inferior angle of the palm, 
which is slightly produced in advance, the appearance 
of a strong thumb, hollowed upon its internal surface. 
From this peculiar character the specific name of the 
animal is derived. The finger is scarcely as long as the 
palm, and impinges throughout its entire length against 
that part of the joint. The other legs do not appear to 
differ much from those of M. monoculoides , except in the 
unimportant circumstance that the posterior margin of 
the second joints of the two posterior pairs of legs are 
not crenulated, and the spines that arm the distal ex- 
tremity of the feet are crenulated upon one side, and 
curved at the tip into an imperfect hook, with a small 
subapical process in the opposite direction, the apices 
F 
