CETJSTACEA OF THE MEEGTJI AECHIPELAGO. 121 



of its fingers. The latter in tlie adult male are but a little 

 longer tlian 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. trian- 

 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 

 granulated 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 o^ G. annulipes, being a little longer 

 than the index, gradually tapered and strongly arcuate towards 

 its pointed tip. The outer surface is faintly longitudinally 

 grooved, 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. triangtdaris, 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 



