CRUSTACEA OF THE MEEGUI AECHIPELA&O. 263 



flattened, especially on its distal half, and is bordered by two 

 longitudinal and parallel crests, of which the external one, how- 

 ever, scarcely extends proximally beyond the oblique impressed 

 line at the base of the outer surface of the hand, whereas the 

 internal crest is a little longer. Immediately before the articu- 

 lation of the mobile finger, a small transverse groove occurs on 

 the upper surface of the palm, as in Alpheus malabaricus (Fabr.), 

 de Haan. The under, like the upper, margin of the palm is flat- 

 tened ; so that an under surface may be spoken of. As already 

 observed, the inner margin of this under surface is bordered with 

 rather long hairs. The mobile finger is strongly compressed 

 laterally, and is broad and bluntly rounded at its distal extremity ; 

 the elevated proximal half of the inner margin of the immobile 

 finger is fringed with rather long hairs on the inner side of the 

 hand, and the outer and inner surfaces of the fingers are also a 

 little hairy. 



The other leg measures 39 millim., is much shorter than the 

 former, and scarcely twice as long as the carapace. The hand 

 of this smaller chelipede is 22^ millim. long, the palm measuring 

 8| millim., so that the fingers are only once and a half as long 

 as the palm. The palm is compressed and fringed with long 

 hairs along the upper and under margins of its inner surface; 

 the fingers are slightly arcuated and present a sjDace between 

 their inner margins, Avhich are densely clothed with rather long 

 hairs, and the tips cross when closed. 



The joints of the carpus of the second pair of legs are respec- 

 tively 4|, 3|, 14-, 1^, and If millim. long ; the first or proximal 

 joint is therefore the longest of all, and even a little longer than 

 the second, and the latter is nearly as long as the three distal 

 joints together. 



The younger specimen, which is only 34 millim. long from the 

 tip of the rostrum to the end of the terminal segment of the 

 abdomen, presents only two slight differences from the adult 

 worthy of notice. The rostrum, as in the adult Alplieus rapax 

 (Eabr.), de Haan, extends backwards nearly to the middle 

 of the carapace, and the antennal scales scarcely jDroject beyond 

 the peduncles of the internal antennae. This specimen in other 

 respects perfectly resembles the adult. 



This species is closely allied to the Japanese Alpheus malaha- 

 ricus (Fabr.), de Haan, and A. Kingsleyi, Miers. It differs at 



