CRUSTACEA OE THE MEEGTJI AECHIPELAGO. 265 



of all, but the second joint. In other respects this species 

 almost completely resembles A. Irevirostris, for the crests with 

 which the outer surface of the larger hand should be provided, 

 according to the author of the ' Pauna Japonica,' may be perhaps 

 visible in very old specimens ; in younger individuals, such as the 

 one before me, they are, however, rather indistinct. De Haan 

 himself describes the upper crest of the outer surface as " valde 

 obtusa evanida." 



The specimen is 55 millim. long from the tip of the rostrum to 

 the end of the terminal segment of the abdomen, and had doubt- 

 less not yet reached its full size. The rostrum extends nearly to 

 the middle of the carapace ; its acute tip projects nearly as much 

 forwards as in A. hrevirostris, scarcely reaching beyond the middle 

 of the antepenultimate joint of the peduncle of the internal 

 antennae. The rostrum is acute between the eyes, and is sepa- 

 rated from them by rather deep depressions ; behind the eyes, 

 however, the rostrum is not acute, but rather obtuse. As regards 

 the length of the joints of the internal antennae, A. rapax fully 

 agrees with A. Irevirostris ; the scale of the external antennae 

 in the specimen scarcely projects beyond the peduncle of the 

 internal antennae. The outer maxillipeds resemble those of 

 A. hrevirostris, and equally project forwards. 



The right chelipede is the larger, as in the figure of the ' Fauna 

 Japonica,' and is 39 millim. long. It therefore appears more 

 than twice as long as the carapace, but shorter than the whole 

 body — quite as in A. Irevirostris. The upper margin of the arm 

 of each chelipede is armed with a small acute spine at its distal 

 end; the inner margin of the upper surface presents some small 

 teeth, of which the distal one is the longest,, resembling those of 

 the preceding species. The larger hand is 22^ millim. long, and 

 7f millim. broad near its base, so that it is about three times as 

 long as broad ; also in the length of the fingers this species 

 agrees with A. hrevirostris. The shape of the larger hand is 

 nearly quite the same in both species, but in A. rapacc no trans- 

 verse groove is found on its upper surface, close to the articula- 

 tion of the mobile finger. I may add that in this specimen the 

 inner surface of the palm is nearly glabrous. 



The smaller hand is similar to that of A. hrevirostris, but 

 the palm is comparatively shorter in proportion to the length of 

 the fingers, the whole hand being 18| millim. long, the upper 



