110 DE. J. G. DE MAJf OK THE PODOPSTHALMOITS 



obliquely forwards. In the adult male the antero-lateral margin * 

 of the carapace makes a very obtuse angle with the postero- 

 lateral, so that the former is easily distinguised from the latter, 

 when the upper surface of the carapace is viewed from above, 

 as in fig. 2. But at a somewhat younger age the postero-lateral 

 margin often does not form an angle with the antero-lateral, so 

 that in these individuals both margins form a single straight line 

 which extends obliquely backward from the external orbital angle. 

 The upper surface of the carapace therefore in these cases has a 

 somewhat different shape, and a specimen presenting this cha- 

 racter has been figured by Mr. Hilgendorf (Taf. iv. fig. 1). But 

 in other males of the same size the carapace resembles that of the 

 first described adult form. In the female, the lateral margin often 

 appears minutely granular, but it is smooth in the male. In the 

 adult male the postero-lateral margin becomes indistinct long 

 before it reaches the posterior margin of the carapace, but in 

 the female it remains visible for more than half its length. In 

 consequence of this oblique course of the lateral margins, the 

 carapace is much narrowed posteriorly and is broad in front. 

 The inferior margin of the orbits is minutely crenulate, both in 

 the male and in the female, except a small internal portion of 

 it, about as long as the external autennse, which is entire. This 

 inferior orbital margin appears everywhere simple, and does not 

 present even a trace of that accessory line which occurs very 

 distinctly in Gelasimus forceps^ M.-Edw. The pterygostomian 

 regions are very convex, somewhat rugose, and covered with 

 short hairs, both in the male and in the female. 



The male abdomen closely resembles that of Gelasimus arcu- 

 atus, de Haau, the fifth joint being the longest of all, and the 

 sixth being a little shorter than the fourth. 



In its general appearance the larger chelipede of the male 

 seems closely to resemble that of Gelasimus arcuatus of the 

 'Eauna Japonica.' The upper margin of the arm is a little 

 granular, and the anterior margin is provided with some small 

 acute, unequal teeth at its distal end ; the anterior and the 



* The epibranchial angle is that point where the lateral margin of the 

 cephalothorax is crossed by the oblique line which is found on the lateral surfaces 

 of the carapace. The antero-lateral margin is the line between the external 

 orbital angle and the epibranchial angle ; and the postero-lateral margin is the 

 rest of the lateral margin. 



