792 



THE VOYAGE OF H.M.S. CHALLENGER. 



Length, entire (male), 

 of carapace, . 

 of rostrum, 

 of pleon, 



of third somite of pleon, 

 of sixth somite of pleon, 

 of telson, 



Habitat. — Tahiti. From a river at Papeuriri. Five specimens, full-grown males. 

 Length, about 125 mm. (5 in.). 



Kandavu and Ovalau, Fiji Islands. Twenty-three specimens ; twenty-two males, one 

 female. Length, male, 110 mm. (4 - 3 in.); female, 69 mm. (2"7 in.). 



Pasananca, Mindanao, and near Samboangan, Philippine Islands. Five specimens; 

 four full-grown males, and one female. Length, male, 125 mm. (5 in.); female, 78 mm. 

 (3 in.). 



Banda Island. Three specimens, females. Length, 52 mm. (2 in.). 



Observations. — This species and that described by Olivier, under the name of 

 Palsemon ornatus, are probably identical with that which Fabricius named Palsemon 

 longimanus, and Milne-Edwards says that it has been taken at Amboina, Waigou, and 

 several places in the Indian Ocean. A considerable number was brought home by the 

 Challenger from the localities given above ; and a close comparison of the numerous 

 specimens leads to the conclusion that they all belong to the same species, although 

 those from each locality show a variation in some unimportant feature that is peculiar 

 to them alone. 



Most of those procured from the river Papeuriri in Tahiti are about 125 mm. long, 

 measured from the margin of the orbit to the extremity of the telson, and the long 

 chelate second pair of pereiopoda is 275 mm. in length, or one-third longer than the 

 animal. 



The dorsal surface is of a purple colour, and it is probable that the whole animal 

 may have been of a similar hue before it was placed in spirits, excepting probably the 

 long arms, which are darker, the digital processes being almost black. 



The finest specimen from Tahiti is rather larger, being 15 mm. longer and more 

 robust, and the only trace of the purple colour that remains is to be found on the 

 posterior margin of the teeth on the rostral crest. The long arms are of a brownish 

 colour, deepening to a purple on the long, digital processes of the chela, and they are 

 about 220 mm. in length. Those obtained at Ovalau and Kandavu are smaller, being only 

 110 mm. long, and not quite so robust. The chelate pereiopoda are about the same 

 length, and of a brownish colour, the digital processes having the colour broken into 

 spots. The purple hue still remains on the posterior margin of the teeth on the rostral 

 crest. 



