114 DE. J. G. DE MAK ON THE PODOPHTHALMOTJS 



different form of the larger hand of tlie male, tlie index of whicli 

 is constantly armed with two teeth, whereas the immobile finger 

 of the larger hand of G. Dussumieri is armed with only one. 



The cephalothorax of the largest specimen closely resembles the 

 variety of G. Dussumieri 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. Dussumieri, 1st by its lengtli 

 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. Dussumieri. The median 

 furrow of the front of G. acutus is constantly very broad and 

 much broader than the lateral margins of the frout, beyond the 

 middle of which it extends ; by this character it therefore differs 

 from G. Dussumieri. As in that species, the upper orbital 

 margin is bordered below by an accessory 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 G. Dussumieri, 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. Dussumieri in the form and the structure of the infe- 

 rior orbital margin, of the pterygostomian regions, of the outer 



