114 DR. J. G. DE MAN ON THE PODOPHTHALMOUS 
different form of the larger hand of the male, the index of which 
is constantly armed with two teeth, whereas the immobile finger 
of the larger hand of G. Dusswmieri is armed with only one. 
The cephalothorax of the largest specimen closely resembles the 
variety of G. Dussumiert described above, which is distinguished 
by the antero-lateral margin of the cephalothorax not making 
an angle with the postero-lateral, so that both margins form a 
single line directed obliquely backwards. In G. acutus also 
the antero-lateral margin never makes an angle with the 
postero-lateral, at least in none of the Mergui specimens, in the 
largest of which the distance between the external orbital angles 
is 25 millim. Nevertheless the cephalothorax may be distin- 
guished even from that variety of G. Dusswmiert, 1st by its length 
being somewhat shorter in proportion to its breadth, and 2nd, 
by the form of the frontal furrow. 
The narrow front is scarcely constricted between the insertion 
of the eye-peduncles, and the rounded anterior margin presents 
a minute median incision, as in G. Dusswmiert. The median 
furrow of the front of G. acutws is constantly very broad and 
much broader than the lateral margins of the front, beyond the 
middle of which it extends ; by this character it therefore differs 
from G. Dusswmiert. As in that species, the upper orbital 
margin is bordered below by an accesysory line, which is a little 
more distinctly granulated. The external orbital angles are very 
acute and directed obliquely forwards. The epibranchial angle is 
indistinct, the antero-lateral margin not making an angle with the 
postero-lateral. As in Gt. Dussumiert, the oblique line which 
occurs on the lateral surface of the cephalothorax does not reach 
the lateral margin, but ceases at a short distance from it. The 
lateral margins are directed very obliquely backward, are minutely 
granulated, and, as in G. Dussumieri, disappear long before reach- 
ing the posterior margin of the cephalothorax. The upper 
surface of the latter is very convex and arcuate longitudinally ; 
although the surface seems to be smooth, it is found, when 
examined under a magnifying-glass, to be minutely granular 
and punctate, and more distinctly so in the female than in the 
male. 
Both the males and the females of this species fully agree 
with G. Dussumiert in the form and the structure of the infe- 
rior orbital margin, of the pterygostomian regions, of the outer 
