1910.] J. R. HENDERSON & G. Matruat: Freshwater Prawns. 297 
The large chelipedes are stout and always unequal in length , 
the longer chelipede which may be either the right or the left is 
much stouter than the shorter one; they are well provided with 
long setose hairs. The upper surface of all the joints is roughened 
by minute close-set spinules, which are best developed on the car- 
pus, while those on the under surface are fewer, but somewhat 
better developed and more erect ; only a few spinules occur on the 
basis while in the longer chelipede those on the palm are confined 
to its proximal upper surface. Traversing the dorsal surface of 
the carpus is a longitudinal groove proceeding from the upper 
protuberance or knob on the inner side of its distal end; this groove 
is, however, very faint in some specimens and in a few it is 
absent. ‘The following are the chief characters of the longer and 
larger chelipede. ‘The setose hairs on the palm and basal regions 
of the fingers are matted together to form a velvety covering. 
The lateral groove on the outer surface of the ischium which is 
generally present in other freshwater prawns is very faint or 
even absent here, while that on the inner surface is specially deep. 
The two inner knobs generally present on the distal end of the 
carpus are specially prominent in this species, and the groove 
between them is very deep. ‘The palm is compressed dorso- 
ventrally ; its length in relation to its width varies from about two 
to one to about three to one; it is wider than the distal end of 
the carpus. ‘The fingers are of nearly equal thickness ; the immo- 
bile finger is slightly concave internally and the mobile one has 
almost the same curve; the tip of the mobile finger is more strong- 
ly incurved than that of the immobile one, so that when the 
fingers are closed it crosses the immobile finger at a short distance 
from the tip. There is a row of from 17 to 26 tubercles on the 
median ridge of the mobile finger, and from 12 to 20 on the im- 
mobile finger; these tubercles gradually decrease in size towards 
the distal end; the third or fourth tubercle of the mobile finger is 
the largest and the basal tooth of the immobile finger fits in behind 
it. When the fingers are closed their opposed margins do not 
meet. There is great variation in the relative lengths of the 
joints; the carpus is generally shorter than the merus, but in 
some cases it is equal to or even slightly longer than the latter : 
the palm is longer than the carpus ; the fingers are usually much 
shorter than the palm, but in some cases, they are either equal to 
it or even slightly longer. The larger chelipede is longer than the 
body. The smaller chelipede differs from the larger one in the 
following respects: —The palm is as wide as the distal end of the 
carpus, and the setose hairs with which it is provided are not 
matted together. The fingers are equal, and their tips are very 
slightiy incurved; the tubercles on their ridges are poorly deve- 
loped towards the distal end, and in some cases are totally absent ; 
when closed their margins meet. The palm is generally sub-equal 
to the carpus, sometimes even shorter ; the fingers are always lon- 
a than the palm. ‘The shorter chelipedes is shorter than the 
ody. 
