CRUSTACEA OF THE MERGUI ARCHIPELAGO. 283 
tions as in the largest specimen, and the fingers are of a fine blue 
colour with white tips. 
As regards the other legs, I may add that those of the third 
pair are quite as long as the antennal scales, and that those of the 
fifth pair do not project so much forwards, reaching only to the 
distal end of the peduncles of the internal antenne. These legs 
are also minutely scabrous. The propodites of the legs of the fifth 
pair are still a little longer than the meropodites and about twice 
as long as the carpopodites. 
The species with which our P. acutirostris is most closely allied 
are the following :— 
(1) Palemon asperulus, v. Mart., from Shanghai, seemingly 
differs from P. acutirostris in its rostrum, having only two or at 
most three teeth of the upper margin situated behind the anterior 
margin of the carapace; by the carpopodite of the anterior legs 
being comparatively shorter, and by the carpopodites of the legs 
of the second pair being not shorter than the arm. 
(2) P. boninensis, Stimps., from the Bonin Islands. This 
form is scarcely different from P. acutirostris, and may perhaps 
prove to be merely a local variety. 
(3) PB. japonicus, de Haan, which differs from it by the shorter 
fingers of the larger hand of the second pair, which are precisely 
half as long as the palm, and by some other characters. 
(4) P. brevicarpus, de Haan, also from Japan. In this form 
the fingers of the larger hand of the second pair are quite as long 
as the palm. 
P. acutirostris, Dana, has hitherto, so far as I know, been only 
recorded from the Sandwich Islands. 
157. PALEZMON EQUIDENS, Dana. 
Paleemon equidens, Dana, United States Expl. Exped., Crustacea, 
i. p- 591, tab. xxxix, fig. 2. 
Four specimens collected in fresh water I refer to P. equidens, 
Dana. Unfortunately all these specimens have lost their second 
pair of legs, except one male, in which one of the legs, probably 
the smaller one, has been preserved; I can therefore add little 
to Dana’s description. 
The formule for the teeth of the rostrum of these four spe- 
' 9 9 10 10 e910 
cimens are: 7, zg 4 and = ; so that the formula is 77. The 
first two teeth are placed on the carapace behind the anterior 
