130 
GAMMA. RID/E. 
of which is fixed below the apex of the plate ; the third 
joint is likewise formed into a squ ami form plate, much 
smaller and more rounded than the preceding, and fur- 
nished at the apex with a few plumose hairs. The arms 
are long and slender, and differ but little from each 
other. They are very imperfectly subchelate. The 
first pair are rather the more robust of the two ; the 
hand is much shorter, and has the inferior margin more 
convex ; the palm is very oblique, and not defined ; 
throughout the whole of the inferior margin, including 
the palm, the joint is furnished with fasciculi, or rather, 
short rows of hairs, most of which are short and simple ; 
but there exists one or two in each fasciculus much 
longer than the rest, straight and plumose : the wrist 
is longer than the palm, and has the inferior margin 
furnished with several short transverse rows of simple 
hairs : the finger is half the length of the hand, and 
is tipped with an unguis or nail, and armed upon the 
inner side with three or four strong spines, furnished 
with a serrated or spinous edge. The second pair of 
arms are rather longer than the first : the wrist is fur- 
nished with long plumose hairs, planted in short trans- 
verse rows, laterally to the inferior margin ; the hand is 
long, and of nearly equal breadth throughout, without 
any distinguishable palm, the inferior margin is fur- 
nished with several short transverse rows of simple and 
plumose hairs; the finger is but one-fourth the length of 
the hand, — it is unguiculate, and has the inner margin 
armed with five or six small spines. The third and 
fourth pairs of legs resemble each other, and differ in 
form from those of other Amphipoda, the fourth joint 
being long and broad, making a long ellipse, convex 
upon the outer, and flat upon the inner surface, and 
