256 ZOOLOGISCHE MEDEDEELINGEN — DEEL III. 

bile finger regularly convex, without longitudinal rim. Species 
found in British India. : Ses. dussumiert. H. Milne-Edwards '). 
These characters not combined 3 
3° Tubereles at upper border of movable. finger of cheliped scalari- 
form, flattened above, asymmetrical. with respect to their long axis 
(which is perpendicular to the long axis of the finger), proximal slope 
longitudinally striated. 4 
Tubercles at upper border of movable finger of cheliped symme- 
trical, proximal slope not longer than distal one, sometimes replaced 
by a row of spines. 6 
4 Chelipeds unequal; upper border of movable finger with 18—19 
tubercles; outer surface of immobile finger with longitudinal rim, 
parallel to the under border; length of immobile finger exceeding 
that of palm. Ses. haswelli de Man. 
Chelipeds equal; upper border of movable finger with only 7—10 
tubercles; length of immobile finger less than that of palm. 5 
D Said tubercles numbering 7—9, proximal slope elongated, with 
a small, smooth, quadrangular portion in the middle, 
in the shape of a human finger-nail, last tubercle very long, occu- 
pying more than one-fifth of the whole length of the finger. 
Ses. onychophora de Man. 
Said tubercles numbering 9—10, somewhat oblique with respect 
to longitudinal axis of finger and arranged in 4—5 groups, each of 
which is composed of two tubercles of different aspect: the proximal 
tubercle of each group is horse-shoe shaped, with the concavity turned 
towards the tip of the finger, and the distal tubercle is straight, the 
proximal slope being vaulted transversely and striated longitudinally. 
Ses. livida A. Milne-Edwards. 
6 Sides of carapace somewhat diverging posteriorly. Upper 
1) In his ,,Materials for a carcinological fauna of India” (Journ. As. Soc. Bengal, v. 69, 
prt. 2. 1900, p. 415) Alcock unites Ses. dussumieri, haswelli and livida with Ses. bidens. It is 
true, that these four species present a striking resemblance to each other, but before more 
specimens and especially adult ones of each are examined, we are not justified to accept Alcocks 
synonymy. Moreover, among other characteristics, the size of the abdomen of the ¢ distin- 
guishes Ses. dussumtert from Ses. bidens, as in the former species the posterior margin of the 
penultimate segment is 1} times its length, in the latter twice this length. 
