CEUSTACEA OF THE MERGUI AECHIPELAGO. 63 



occupies the proximal tbird of the outer surface. In the largest 

 specimen, on the contrary, the larger proximal half of the outer 

 surface is granulo-spinulous, and some granules are also found at 

 the proximal end of the under margin. The granules of the 

 granulo-spinulous area are of unequal size and are acute ; sonie 

 larger granules are often observed in two rows on the upper 

 margin, and irregularly spread over the outer surface, whereas 

 others of smaller size are distributed between the large gra- 

 nules. In other specimens the granules which are found on the 

 uj)per margin are smaller than those of the outer surface. The 

 somewhat convex inner surface of the palm is quite smooth in 

 the three smaller specimens, but a little granular on the middle 

 in the largest. The dark-coloured fingers are shorter than the 

 palm, and are nearly similar to those of P. vespertilio] they 

 meet along their inner margins, and have pointed, crossed tips. 

 The mobile finger is covered above at its base with a few 

 granules, but otherwise it is quite smooth and glabrous, pre- 

 senting, however, some longitudinal lines of punctulations. The 

 inner edge is feebly denticulate, a somewhat larger (longer) 

 tooth being found at the base, and the inner surface bears a few 

 small tufts of short hairs along the inner edge. The immobile 

 finger presents an impressed, punctate, longitudinal line on the 

 outer and on the inner surface ; its inner margin is provided with 

 six teeth, which are stronger than those of the mobile finger, and 

 the third of which is the largest ; on the inner surface this finger 

 also bears a few tufts of short hairs. 



The hand of the smaller chelipede is much smaller and com- 

 paratively more slender than the larger hand. The smaller hand 

 is a little shorter than the other, but much lower, its height mea- 

 suring scarcely more than a third of the length, the fingers 

 included. The whole upper surface of the palm, including its 

 upper and under margins, is covered with some large acute gra- 

 nules, which are comparatively a little larger than those of the 

 larger hand, and are mostly arranged in six or seven longitudinal 

 rows, two of which are iound on the upper margin. The inner 

 surface of the palm presents some acute granules. The fingers 

 of the smaller hand, which are shorter than the palm, meet 

 along their inner margins, and have also pointed crossed tips. 

 The lower finger is slightly deflexed, and rather profoundly 

 sulcate both on its outer and its inner surface ; the inner margin 

 is armed with five or six teeth. The mobile finger, which is 



