CRUSTACEA OF THE MERGUI ARCHIPELAGO. 167 
and much shorter than it is broad at the base; the second joint 
also nearly resembles that of If. elegans, being trapezoidal and a 
littie longer than the first ; the following joints, however, are all 
more enlarged than in the preceding species, so that, e. g., the third 
joint is more than twice as broad at its posterior margin as it 
is long. The lateral margins of the abdomen and the anterior 
margins of the segments (except those of the first and the 
second) are fringed with longer hairs than in the two preceding 
forms. 
The chelipedes of the male are somewhat similar to those 
of MW. elegans, but the hands are shorter, and the palm is as 
long as broad (high) ; in all other species of the genus Metaplax 
which are described is this report, the hands are more or less 
elongate, the palm being always longer than broad. The cheli- 
pedes are a little unequal, the right or the left being the larger 
one. In the larger specimen, the cephalothorax of which is 12 
millim. broad, the arm of the larger chelipede reaches laterally 
nearly to the middle of the meropodites of the third and 
fourth legs. The arms are similar to those of IZ. elegans. The 
musical crest lies on the middle of the anterior margin of the 
upper surface. The inner margin of the wrist is granular. The 
hands much resemble one another. The larger hand is scarcely 
twice as long as it is broad (or high) at the base of the fingers ; 
the palm is as long as broad at the base of the fingers, being here 
53% millim. broad, and having the same length; the fingers are 
scarcely shorter than the palm. The hands are rather com- 
pressed; the upper and the under margins of the palm are 
granular, like its inner surface, except near the articulation of 
the immobile finger, where it is smooth. The outer surface 
appears smooth to the naked eye, except near the under margin 
and near the articulation with the wrist, where it is minutely 
granular. The fingers resemble those of J. elegans; the pro- 
minent lobe, however, with which the inner margin of the mobile 
finger is armed, is not found in the middle of it, but nearer to the 
articulation, and the lobe presents a more quadrangular form, 
whereas the immobile finger appears comparatively higher at its 
proximal half. 
The ambulatory legs generally resemble those of MW. elegans. 
The meropodites, however, are only armed with one single spine 
near the distal end of their upper margin; the carpopodites and 
propodites are less slender, and the dactylopodites are compara- 
