A.MPHIPODA. 297 



Palp iif tin- 1st maxillae with the 2nd joint not wider than the 1st and not 

 expanding distally (rig. 52. nix. 1 ). 



( >ther mouth organs as in P. inconspicuum, Steb. (' Chall. Ainph.,' p. 1194. pi. cxxxi.). 



First gnathopods: side-plates small, produced to a blunt point with a setule. 

 First joint slant and stout, longer than the next 2 ; wrist shorter than the hand, but 

 fully as wide, the front margin with curved spines, the hind margin flattened and 

 densely setose ; the hand has the hind margin concave near the base, with a straight 

 and very setose palm ; the trout margin convex (fig. 52. gn. 1 6). 



Second gnathopods of male : side-plates oblong, wider than deep, rounded in front. 

 First joint about half as long as the hand, 3rd joint convex and setose, with the hind 

 margin produced distally. Wrist merged in the hand, which is narrow-oval, with the 

 hind margin slightly concave and densely setose ; the palm is undefined. The front 

 is convex, with groups of spines. Dactylus reaching rather beyond the middle of the 

 hind margin (fig. 52. gn. 2 8). 



The gnathopods in the female much resemble those of P. inconspicuum, Steb., but 

 the wrist of the 1st pair is as wide as the hand, and the point of the dactylus is not 

 divided as in that species. In the 2nd pair the 3rd joint is more produced behind, 

 and the wrist, which is quite distinct, though small, is not produced at all (fig. 52. 



g- a ?) 



First and 2nd pereeopods : first joint narrow and subequal to the 4th, with long 



spines on the front margin ; the 5th the longest, its hind margin, with 5 spines, 

 increasing in length distally (fig. 52. pp. 1 ). 



Third perseopods : side-plates bilobed, the front lobe the larger. First joint with 

 the lamina projecting beyond the proximal part of the hind margin, the distal part 

 fringed with slender, unequal spines ; 3rd joint acutely produced behind ; 5th joint 

 rather shorter than the 3rd and 4th together; the whole limb spinous (fig. 52. pp. 3 ). 



Fourth and 5th pera^opods resembling the 3rd, except in the 1st joint, in which 

 the posterior lamina is continuous along the hind margin (fig. 52. pp. 5 ). 



Uropods : the outer ramus of the 1st as long as the inner of the 2nd, the peduncles 

 shorter than the inner rami : the whole spinous (fig. 52. ur.). 



The 3rd pair small and spoon-shaped, with a setule on the inner margin, barely 

 i 'i-iiing beyond the end of the telson. 



Telson as in the last species, but with 2 groups of 3 or 4 spines on each side. 



Length of adult male, 6 '5 millims. Female, with ova, 3 '5 millims. 



Platophium zeylauicum, n. sp. Plate VI II., rigs. 53. 



From pearl oysters. Easf Cheval Paar, November, 1902; several. 



Segments of mesosome and pleon dorsally depressed in the middle, not carinate or 

 dentate. Urus with 3 segments, the division between the 2nd and 3rd somewhat 

 indistinct. Head shorter than the first 2 segments. Ocular lobe little produced. 

 Eyes round and prominent. 



2 Q 



