Ps ae 
a, 
v; 
CRUSTACEA OF THE MERGUI 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 
174:18, whereas in S. sinensis the numbers are respectively 
174:93. In S. 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 S. 
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 SN. 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 Sesarme closely resemble each 
other. 
Dimensions of the largest specimen :— 
| milftm 
Distance between the extraorbital teeth ...... » 133 
iMenethvol thescephalothorax 22... 22.2 sev. 404: 113 
Breadth of the front, measured between theeyes.. 83 
Sesarma intermedia has been recorded from Japan, Hong- 
kong, Shanghai, and from the coast of Java. 
101. Szesarma,n. sp.? (Pl. XII. figs. 18-15.) 
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 S. intermedia and SN. 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 S. intermedia, the proportion of the distance between 
