178 DR. J. G. DE MAN ON THE PODOPHTHALMOUS 
miert than in S. bédens ; the fourth joint is also comparatively 
shorter and appears therefore more enlarged in this species than 
in de Haan’s; the fifth joint has nearly the same form in both 
species. The penultimate joint, however, in S. Dusswmieri is 
comparatively much longer than in S. bidens, the proportion of 
the breadth of the posterior margin to the length of the joint 
being as 7: 44, and in S. bedens as 7:34; this joint, moreover, is 
more narrowed towards the terminal segment, the breadth of 
the posterior margin being in proportion to the breadth of the 
anterior margin as 7: 8, but in S. bidens as 7:4. The lateral 
margins of this joint are also a little more rounded than those 
of S. bidens. The terminal joint is comparatively longer in 
S. Dussumiert than in S. bidens. 
The anterior legs or chelipedes of S. Dussumieri are very dis- 
tinctive of the species, and are, as in S. bidens, equal to one 
another. The upper margin of the arm of S. didens terminates 
at the distal end in a short acute tooth, which is not found in 
S. Dussumert. In the species of the ‘Fauna Japonica’ the 
anterior margin of the merus-joint is armed with a simple, 
strong, acute spine, but in S. Dussumieri this spine is repre- 
sented by a prominent triangular tooth, the margins of which 
are denticulate. 
In the general appearance of the hands and the proportion 
between the length of the fingers and of the palm, this species 
is very similar to S. bidens. The hands, however, present the 
following distinctive characters :—the outer surface of the palm 
and of the fingers in S. Dussumiert 1s more convex than in 
S. bidens, and the outer surface of the immobile finger is 
convex and quite smooth; whereas in S. bzdens, S. Haswelli, 
aud S. guttata it is flattened or even very slightly concave, 
somewhat granular and bordered below by a slight ridge-like 
elevation, parallel to the under margin. The outer surface 
of the palm is granular, as in S. bidens, but the granules 
gradually disappear towards the base of the immobile finger. 
In 8. Dussumieri the inner surface of the palm is much more 
granular than in all the other species of this section, presenting 
many prominent, acute, subspiniform granules of different sizes, 
the largest of which are found about the middle of the inner 
surface. The two pectinated ridges are a little longer and 
somewhat more oblique in this species than in S. db¢dens, and 
when the hands are in the ordinary position of rest, lying close 
to the cephalothorax, these ridges lie in a transverse direction, 
