’s RIJKS MUSEUM VAN NATUURLIJKE HISTORIE — LEIDEN. 257 
border of movable finger of cheliped with a row of 6—7 acute 
spines, occupying the proximal two-thirds of the finger. 
Ses. siamensis Rathbun. 
Sides of carapace converging posteriorly. Upper border of 
movable finger of cheliped always with a row of obtuse tubercles. 7 
Said tubercles numbering about 23, each of which is about 2'/, 
times as long as broad (at least in the middle of the row, where 
they are largest), with a broad groove along its longer axis, the rim 
of which groove is ornamented by transverse striae, perpendicular to 
the longer axis of the tubercle; on the distal tubercles this groove 
disappears and the proximal slope becomes longer than the distal one, 
though the fine longitudinal striation remains, save on the 3—4 last 
tubercles near tip of finger. Ses. eumolpe de Man. 
Said tubercles numbering 7—13, not grooved along their longer axis. 8 
Said tubercles numbering 7, strongly prominent, dome-shaped. 
Carapace strongly convex, smooth and shining. Ses. semperi Bürger. 
Said tubercles numbering 12—13, less prominent, broader than 
long, proximal slope striated. Ses. bidens (de Haan) ') 
B. Metasesarma. 
Sides of carapace convergent posteriorly. Outer surface of palm 
of cheliped covered with spiniform granules. Metases. trapezium (Dana). 
Sides of carapace convexly arched in their anterior part or parallel 
to each other. Outer surface of palm of cheliped smooth, punctate. 2 
Inner infra-orbital lobe often in contact with the lateral processus 
of the anterior margin of the front, in such a way, that the orbital 
lobe in outer view is concealed by the frontal processus (though also 
the reverse may be observed); not rarely, however, there is a more 
or less wide gap between this orbital lobe and the frontal processus, 
so that the outer antenna is not excluded from the orbit; width of 
front always more than half the greatest breadth of 
the carapace. Metases. rousseauxi H. Milne-Edwards. 
1) In the subspecies zzdica de Man there are only 11 tubercles on the upper border of the 
movable finger of cheliped; these tubercles are approximately quadrate, with both axes nearly 
equally long, and the finely-striated proximal slope is somewhat longer than the distal one; 
the posterior margin of the: penultimate segment of the abdomen of the 4 is somewhat less 
than twice the length of this segment, whereas it is more than twice this length in the 
typical species, 
