178 DR. J. Or. i)E MAN ON THE PODOPHTHALMOtlS 



W2er« than in ;S^. hidens ; the fourth joint is also comparatiyely 

 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 B. Dussumieri is 

 comparatively much longer than in S. hidens, the proportion of 

 the breadth of the posterior margin to the length of the joint 

 being as 7 : 4|, and in S. hidens as 7 : 3| ; this joint, moreover, is 

 more narrovv^ed towards the terminal segment, the breadth of 

 the posterior margin being in proportion to the breadth of the 

 anterior margin as 7 : 3, but in 8. hidens as 7:4. The lateral 

 margins of this joint are also a little more rounded than those 

 of S. hidens. The terminal joint is comparatively longer in 

 8. Dussumieri than in S. hidens. 



The anterior legs or chelipedes of S. Dussumieri are very dis- 

 tinctive of the species, and are, as in S. hidens, equal to one 

 another. The upper margin of the arm of S. hidens terminates 

 at the distal end in a short acute tooth, which is not found in 

 S. Dussumieri. In the species of the ' Eauna 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 8. hidens. The hands, however, present the 

 following distinctive characters : — the outer surface of the palm 

 and of the fingers in S. Dussumieri is more convex than in 

 S. hidens, and the outer surface of the immobile finger is 

 convex and quite smooth ; whereas in S. hidens, S. Saswelli, 

 and 8. 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 8. hidens, but the granules 

 gradually disappear towards the base of the immobile finger. 

 In S. 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 difierent 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 8. hidens, and 

 when the hands are in the ordinary position of rest, lying close 

 to the cephalothorax, these ridges lie in a transverse direction. 



