CRUSTACEA OF THE MERGUI ARCHIPELAGO. 121 
of its fingers. The latter in the adult male are but a little 
longer than the middle length of the palm. The outer con- 
vex surface of the palm appears wholly smooth to the naked 
eye, but often minutely granular towards the upper margin, 
when examined under a magnifying-glass. On the upper margin 
of the palm a longitudinal groove occurs, which is not found 
on the rounded upper margin of the palm of G. annulipes. In 
both species there is also a longitudinal groove on the under 
margin of the palm, but in G. triangularis it does not extend 
upon the index. The impressed line which occurs in G. annu- 
lipes on the outer surface of the palm, close and parallel 
to the anterior margin, appears very indistinct in G. ¢rian- 
gularis. The fingers are somewhat less compressed than those 
of G. annulipes, but in other respects they are very similar 
in both species. The index is upwardly curved and gradually 
tapers towards its pointed tip; its outer surface and that 
also of the mobile finger appear minutely punctate when ex- 
amined under a magnifying-glass. The inner, rather coarsely 
eranulated margin of the immobile finger is constantly armed 
with two teeth, one at the base and the other near the distal end 
of the middle third of the finger; the subterminal tooth which 
occurs on the index of G.,annulipes is absent. The mobile 
finger is similar to that of @. ammulipes, being a little longer 
than the index, gradually tapered and strongly arcuate towards 
its pointed tip. The outer surface is faintly longitudinally 
erooved, though more distinctly than in G. annulipes, but the 
proximal half of the upper margin appears somewhat granular 
in both species. The mobile finger of G. triangularis is armed 
along its inner, coarsely granulated margin with only two 
teeth, one quite at the base, before the basal tooth of the index, 
and the other almost opposite the second tooth of the latter. 
In typical specimens of G. annulipes the index is also armed, in 
addition to the strong subterminal] tooth which is characteristic 
of G. triangularis, with three other teeth, and the mobile finger 
with about four. | 
The inner surface of the palm often appears granular towards 
its upper margin, and is armed with two strongly tuberculated 
crests, viz. the ordinary oblique crest bordering internally the 
under surface of the palm, and another close and _ parallel 
to the anterior margin. In G. annulipes the inner surface of 
the palm is armed with three crests, two parallel crests being 
