C'RtrSTACEA 01" THE MEEGUI ARCHIPELAGO. 179 



parallel to tlie frontal margin ; in S. hidens, S. Saswelli, and 

 8. guttata, on the contrary, they appear to be directed obliquely, 

 forming an angle \vith tlie frontal margin, when the hands are in 

 the same position. The distal row is composed of 18-22 teeth, 

 the other of a somewhat smaller number. The mobile finger is less 

 granular externally than in S. hidens, presenting some granules 

 only at the base ; it is covered on its upper margin with a 

 row of 12 or 13 transverse prominences, w^hich differ much in 

 form from those of Sesarma hidens and S. guttata. They are 

 scalariform, and closely resemble those of S. Saswelli, each pro- 

 minence being flattened above and more or less declivous at 

 its distal margin ; in 8. Dussumieri, however, they are com- 

 paratively larger than in S. Hasioelli, as well as fewer in number. 

 The granules on the proximal half of the finger, at the inner 

 side of the row of prominences, are more acute in *S^. Hasioelli 

 than in the other species, and nearly subspiniform. The inner 

 surface of the mobile finger is smooth, that of the immobile finger 

 rather granular. 



The ambulatory legs resemble closely those of Sesarma hidens, 

 but the dactylopodites are a little longer in proportion to the 

 propodites, the proportion of the propodites to the dactylopodites 

 of the penultimate pair being in 8. Dusstimieri as 8 : 7, in 8. 

 hidens as 8 : 6. 



Dimensions : — 



millim. 

 Distance between the extraorbital teeth 21^ 



Length of the cephalothorax 18^ 



In a typical specimen from the Paris Museum these numbers 

 are respectively 30 and 25g. 



Sesarma Dussumieri has hitherto been recorded from Bombay ; 

 it thus inhabits the northern part of the Indian Ocean. 



98. SeSABMA LITIDA, ^. Jlf.-^f/ty. .->,.■.;!, P-b'k-^; 



Sesarma lividum, Alph. Milne-Edwards, Nouv. Archives du Museum 

 Hist. Nat. t. V. Bulletin, p. 25 (1869), and t. ix. p. .ms, pi. xvi. fig. 2-(1873). 



Seven young male specimens were collected — three from the 

 mangrove-swamps at Zedi\son, one from Kissei'aing, and three 

 specimens elsewhere. These I refer with some doubt to this 

 species. 



8esarma livida is the fifth species of this section of the 

 genus, and has hitherto been known only from the seas of New 

 Caledonia. It is closely allied to the four other representatives 

 of this section mentioned above. Its cephalothorax resembles so 



12* 



