96 
GAMMARLDiE. 
running across the axis of the joint, and covered below 
and at the apex with a fur of short hairs, amongst which 
the small finger is lost to observation, except under very 
high magnifying power. It must therefore appear, if 
there be any prehensile capability in this and other 
similar appendages, that it is not obtained through any 
assistance that can be derived from the finger, but by 
the pressure of the hand back against the hairy cushion 
on the inferior surface of the wrist. The first two pairs 
of walking legs are small, and the last three appear to 
be more robust ; they are rather curved, and have the 
second joint developed to a broad oval shape, which is 
produced infero-posteriorly, so far as to cover the next 
joint; their posterior margins are crenulated, and have 
a short hair springing from the depression between each 
lobule ; the fourth joint is broader in the fifth pair of 
legs than in the two following pairs ; the sixth joint is 
slightly curved, the two margins being parallel. The 
three pairs of caudal appendages are short ; the branches 
(which are of equal length on each) are very short, those 
on the posterior being a little the longest. The terminal 
scale is cleft through more than half its length. The 
tail generally has the appearance of being a powerfully 
thrusting organ, and it is undoubtedly used to propel the 
animal either backwards or forwards. 
The colour of the animal varies from a transparent 
pale yellow, in the young state, to that of a deep yellow 
or light brown tint. The eyes are red in the young, but 
become black in the adult animal. The structure of the 
skin appears not to exhibit any decided markings when 
examined by the microscope, but the surface generally is 
covered with minute solitary spinules or short hairs, dis- 
tantly scattered. 
This description, as well as our figure, is taken from a 
