CRUSTACEA OF THE MERGUI ARCHIPELAGO. 115 
maxillipeds, and even of the abdomen. Stimpson mentions 
a ridge on the subhepatic region, proceeding parallel to the 
inferior orbital margin. In G. acutus, as in G. Dussumieri, 
I observe a glabrous groove, immediately below the inferior 
orbital margin, running parallel to it, and separating this mar- 
gin from the convex, hairy pterygostomian regions. But as I 
have already remarked, this groove is proper to both forms, 
and will probably be found in many other species of the genus. 
G. acutus therefore closely resembles G. Dussumiert in the 
form of its cephalothorax. 
As regards the occurrence of the larger chelipede on the 
right or on the left side: in thirty-four specimens, twenty-one 
have it on the right and thirteen on the left side of the cephalo~ 
thorax. 
In its outer appearance the larger chelipede of the male is 
similar to that of G. Dussumieri, and bears the same propor- 
tion to the cephalothorax. The three margins of the arm are 
granular, and the convex outer (posterior) surface of the arm 
is also covered with small granules; the concave inner surface is 
smooth and a little hairy, but the anterior surface is smooth and 
glabrous. The carpopodite is similar to that of G. Dusswmieri, 
its rectangular upper surface being covered with small granules 
fringed with hairs along the anterior margin. The hand is even 
a little more developed than in G. Dussumiert, so that if 
G. acutus attains the same size as that species, its larger nand 
will probably also become twice as long as the distance between 
the external orbital angles of the carapace. The height of the 
hand (¢. e. of the palm) slightly exceeds a third of the length, 
so that the hands of the two species much resemble one 
another in this character; but the fingers are less elongate and 
shorter in proportion to the length of the palm. In G. acutus 
the fingers are but little longer than the palm, whereas in equally 
large specimens of G. Dussumiert the fingers are once and a 
half as long as the middle length of the palm. The outer 
surface of the palm is granulated in the same manner as that 
of G. Dussumteri, and the upper margin also presents two rows 
of small acute granules, close to one another. 
The immobile finger tapers regularly towards its extremity 
and is considerably curved upward; its outer surface appears 
smooth to the naked eye, but minutely granular with the aid of a 
Qe 
