1909.] OF CRAB FROM THE BAY OF BATAVIA. 665 



rounded, slightly concave at the base of the immobile finger, though 

 not emarginate or notched ; upper border also rounded, but pre- 

 senting, just behind the truncate distal extremity of the palm, a 

 narroio groove, running obliquely inward, though not continued on 

 to the inner surface of the palm ; this groove (PI. LXX. fig. 3) runs 

 parallel with the oblique anterior end of the elliptical area. The 

 dactylus, a little longer than the immobile finger, measures almost 

 one third of the palm and almost one fourth of the whole length 

 of the chela ; the palm is sparsely though distinctly punctate, 

 the inner surface anteriorly, like that of the immobile finger, 

 hairy, the outer surface of the latter longitudinally grooved. But 

 for the oblique groove on the upper border, the larger chela much 

 resembles that of A. paracrinitus var. hengalensis. 



Meropodite of smaller chelipede like that of the larger, but the 

 infero- internal margin, though also with a small acute tooth at 

 the extremity, with only four -or_five movable spinules. Chela 

 5"55 mm, long, the larger chela once and a half as long as the other ; 

 the smaller chela (PI. LXX. fig. 4), the fingers of which are about 

 as long as the palm, is 3*7 times longer than high, the palm twice 

 as long as high, with the upper border entire and rounded, like 

 the lower. 



Meropodite of 2nd legs in the larger specimen 6 times, in the 

 other 6*85 times, longer than wide. In the larger specimen the 

 1st carpal segment, 5*3 times longer than thick, is just twice as 

 long as the 2nd, the 2nd twice as long as the 3rd and as the 4th, 

 which are of equal length, and the 5th a little shorter than the 2nd ; 

 the chela, the fingers of which are a little longer than the palm, is 

 almost twice as long as the 5th segment. In the other specimen 

 (PL LXX. fig. 5) the 1st carpal segment, 6-3 times longer than 

 thick, appears 2-44 times longer than the 2nd, and the 2nd, which 

 is slightly shorter than the 3rd and the 4th taken together, is as 

 long as the 5th ; the chela, finally, the fingers of which are slightly 

 longer than the palm, is I'S times longer than the 5th segment. 



The proportions of the 5th pair (PI. LXX. fig. 6) are: Carpus 1 ; 

 meropodite 1-18; propodite 1-07, Meropodite 5-2 times, carpus 

 6 times, propodite 7 times longer than wide, these members with 

 rather long setae, and the propodite with the usual bristles ; 

 dactylus, as in A. paraa-initus, tapering, acuminate, 4 times as 

 long as wide at its base, slightly curved, simple, without any trace 

 of a secondary claw, and measuring just tioo-Jifths of the propodite. 



Unfortunately the legs of the 3rd and 4th pairs are absent in 

 both specimens, except one leg of the 4th pair in the younger 

 individual ; the meropodite is quite unarmed, the propodite carries 

 6 spinules, and the simple dactylus agrees with that of the 5th legs. 



Alpheus paracrinitus Miers differs by the upper border of the 

 larger chela being entire, without a groove, by the different shape 

 of rostrum and frontal margin, by the shorter stylocerite, and 

 probably by other charactei^s ; A. lanceloti is a more difierent 

 species; and A. macrochirus Richters, finally, difiers at first sight 

 by the flattened, triangular rostrum, by the longitudinal groove 



