134 CRUSTACEANS OF THE 



Rathb. and bears some resemblance to Sesarma angustifrons 

 A. M. E. The male from Tahiti that was referred by my- 

 self, iu 1889, to the latter species (in: Zool. Jahrbücher, 

 Abth. für System. T. IV, p. 432, PI. X, fig. 10), was, 

 upon my demand, kindly sent me by the Direction of the 

 Senckenbergische Gesellschaft at Frankfort on the Main , 

 so that I now am able to indicate the differences. 



The 5 specimens of Ses. Amphinome are, 1 think, still 

 young, none of the females carrying eggs and therefore 

 it is a pity that no more specimens were collected. 



As regards the general shape of the cep halothorax, the 

 new species closely resembles Ses. angustifrons, the slightly 

 concave lateral margins diverging also somewhat back- 

 wards, so that the cephalothorax is broadest above the 

 legs of the antepenultimate pair. The cephalothorax is , 

 however, a little shorter in proportion to the distance 

 between the external orbital angles and the straight pos- 

 terior margin is comparatively broader than in Ses. an- 

 gustifrons. 



In the male from Tahiti the posterior margin is just 

 half as broad as the distance between the outer angles of 

 the orbits and less broad than the front, but iu Ses. Amphi- 

 nome it is considerably broader and distinctly broader 

 than the front. The upper surface is slightly con- 

 vex from before backwards. The interregional grooves are 

 somewhat deeper and more distinct than in the 

 Sesarma from Tahiti ; in the male of Ses. angustifrons the 

 mesogastric region is undivided , but in Ses. Amphinome 

 it is distinctly tripartite. The protogastric regions are 

 covered with some small tubercles anteriorly, immediately 

 behind the post-frontal lobes and the hepatic area is also 

 somewhat tubercular; in the male from Tahiti these small 

 tubercles are not observed. The upper surface of the cepha- 

 lothorax appears finely punctate under a maguifying glass, 

 but the puncta are irregularly distributed. On the tuber- 

 cular anterior half of the protogastric regions, on the hepa- 

 tic area, on the grooves between the three parts of the 



Notes from the Leyden ]Museum , Vol. X^^I. 



