226 CRUSTACEA. 



Moveable finger of larger hand white, smooth, a little scabrous near 

 base, stout. Front irregularly denticulate. 



Plate 13, fig. 2 a, male, enlarged three diameters; b, under view of 

 front, showing base of outer antennae. 



Upolu, Samoan Group; also Tahiti, Society Group. 



Length and breadth of carapax of a male, each six lines. The re- 

 semblance to the preceding species is very close, although the two are 

 separated easily by the characters stated. The anterior part of the 

 lateral margin is rather shorter than the posterior. The granules of 

 the hand in the dried specimen are partly white and partly reddish, 

 the red ones scattered among the others. 



Pilumnus Andreossyi, SAVIGNY, Desc. de 1'Egypte, Crust., p. 86, pi. 5, f. 5. 

 Cymo Andreossyi, DE HAAN, Faun. Japon., 22. 



SUBFAMILY POLYDECTIIO3. 

 GENUS POLYDECTUS, Edwards. 



The species here referred to Polydectus has many characters in 

 common with the P. cupullfer, and the two, evidently, are congeneric. 

 Besides general form and aspect, one of the most striking charac- 

 teristics is the peculiarity of the hand, which is hardly stouter than 

 the following legs, and although short, consists of long, slender fingers, 

 the palm at the base of the fingers being very short. Moreover, these 

 fingers are nearly equal, and have the apices incurved. Another 

 character in common is observed in the orbit, there being three 

 tubercles or lobes forming the under and outer part of the orbital 

 margin ; in the cupulifer these prominences are hollowed out, a spe- 

 cific and not a proper generic distinction. 



The genus Polydectus was transferred to the Corystidae by Milne 

 Edwards, from the genus Pilumnus, where it was placed originally by 

 Latreille. The character of the outer antennae, especially the slender, 

 nearly naked flagellum, removes it from the Corystidae; and it is not 

 related particularly to that family in the form of the outer maxilli- 

 peds. The second joint of these organs is somewhat transverse in our 



