CEUSTACEA OF THE MEEGUI AECHIPELAQO. 167 



and much shorter than it is broad at the base ; the second joint 

 also nearly resembles that of M. elegans, being trapezoidal and a 

 little 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 M. elegans, but the hands are shorter, and the palm is as 

 long as broad (high) ; in all other species of the genus Metaplaoa 

 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 M. 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 

 5|- 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 M. 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 M. 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- 



