562 COLLECTIONS FE05I THE WESTERN INDIAN OCEAN. 



Islands, and may 1)0 identical with it ; but differs from his brief de- 

 scription in some minor points, e.g. in the absence of the small 

 spinules at tho base of the third and fourth legs. 



4. Alpheus minor, var. neptunus, Dana. 



Specimens of this species, whose synonyms and distribution have 

 been referred to at p. 288 of this Report, are in the collection from 

 Darros Island, 22 fms. (No. 185), He des Neufs, 15 fms. (No. 187), 

 and Glorioso Islands, 7-10 fms. (No. 219). 



5. Pontonia? brevirostris. (Plate LI. fig. B.) 



Tho body of this species is shaped nearly as in P. tridaence (Peters). 

 The rostrum is very small, not at all laterally compressed ; viewed 

 dorsally it is triangular and acute, and scarcely prolonged beyond 

 the bases of the eye-peduncles ; the anterior margin of the carapace, 

 near to the antero-lateral angles, is armed with a spine ; the lateral 

 margins of the second to fifth postabdominal segments are obtusely 

 rounded, those of the sixth segment posteriorly spiniform and acute ; 

 the terminal segment is subtriangulate, with the apex subacute 

 (broader and more rounded in the adult female), and bears on its 

 dorsal surface two strong spines near to each lateral margin. The 

 eye-peduucles are subcylindrical, thick, and project laterally. The 

 first exposed joint of the antennulary peduncles is flattened and con- 

 siderably dilated, and has two spines on its outer margin, of which 

 one is at the extero-distal angle of the joint ; the next joint is very 

 short, the terminal joint longer; the outermost of the two short 

 flagella is thickened and shortly bipartite. The antennae are in- 

 serted beneath and outside of the antennules, and their short 

 peduncles in a dorsal view are hidden by the antennal scales, which 

 are large, ovate, and distally ciliated, and prolonged beyond the 

 distal end of the peduncles and the antennules. The slender man- 

 dibles are without a palpus ; the outer maxillipedes are subpediform, 

 with the antepenidtimate joints but slightly thicker and a little 

 longer than tho two terminal joints taken together. The anterior 

 legs are slender and unarmed, with merus and carpus of about equal 

 length, and each about as long as the palm and fingers taken together ; 

 the palm is not dilated, and the fingers are not denticulated on their 

 inner margins. The second legs (in the specimens examined) are 

 but moderately thickened and of nearly equal size; ischium, merus, 

 and carpus of about equal length, but the carpus somewhat thicker; 

 palm longer than the carpus, smooth and rounded, scarcely com- 

 pressed ; fingers about as long as palm, meeting along their inner 

 margins, which are not denticulated. Ambulatory legs slender, 

 with the penultimate joints about twice as long as the preceding; 

 dactyli styliform and acute. The rami of tho uropoda are ovate and 

 ciliated, and the outermost has a small spinule near to the distal end 

 of its outer margin. Colour (in spirit) reddish yellow. The exact 

 dimensions of the larger specimen, owing to its imperfect condition, 



