CBUSTACEA OF THE MEEGTJI ARCHIPELAGO. 183 



of the joints of the male abdomen, the Mergui specimens 

 perfectly agree with the figure in the ' Fauna Japonica.' Both 

 species, however, may be distinguished by the form of the hands 

 and of the ambulatory legs. The hands of these specimens 

 closely resemble those of S. tetragona^ M.-Edw. {^nec Fabr.), the 

 proportion of the length of the fingers to that of the palm, 

 measured at the lower margin, being in both species as 

 17| : 13, whereas in >S'. sinensis the numbers are respectively 

 17| : 9^. In 8. sinensis the fingers, therefore, are much longer 

 in proportion to the size of the palm. The inner surface of the 

 palm is armed with a transverse granulated crest, as in 8. 

 sinensis \ the outer surface is also granular in both species, and 

 the outer surface of the fingers is quite smooth. The upper 

 margin of the mobile finger is somewhat granular at the base, 

 but the rest is quite smooth ; in S. sinensis this finger is also 

 somewhat granular on its upper margin. 



The ambulatory legs also present a good character for dis- 

 tinguishing both species. In S. sinensis the meropodites are 

 slender, those of the first pair being three times as long as 

 broad, whereas in the Mergui specimens they are enlarged, those 

 of the first pair being scarcely twice as long as broad. 

 ' In other respects these two Sesarmce closely resemble each 

 other. 



Dimensions of the largest specimen : — 



6 

 millim. 



Distance between the extraorbital teeth 13| 



Length of the cephalothorax llf 



Breadth of the front, measured between the eyes . . 8f 



Sesarma intermedia has been recorded from Japan, Hong- 

 kong, Shanghai, and from the coast of Java. 



101. Sesarma, n. sp. ? (PI. XII. figs. 13-15.) 



There is in the collection a small Sesarma from Tavoy, which 

 I suppose to be new, but I hesitate to name it as it is an 

 extremely young individual. 



It is closely allied to 8. intermedia and 8. sinensis, but is 

 distinguished from them by the occurrence of an acute spine on 

 the anterior margin of the arms of the first pair of legs. 



The cephalothorax appears to be scarcely more enlarged 

 than that of 8. intermedia, the proportion of the distance between 



