72 THE VOYAGE OF H.M.S. CHALLENGER. 



interval. Auteunal acicle slender, the flagellum naked. Chelipedes subequal and of 

 small size, the right slightly larger ; the fingers moving in a horizontal plane and 

 calcareous at the tips. Second and third pairs of legs with long, flattened and ciliated 

 dactyli. Coxa of the fifth left leg in the male with a long, .sjjirally coiled, membranous 

 organ (formed by a protrusion of the vas deferens), strengthened along its outer surface 

 by a corneous band ; the vas deferens of the right side scarcely produced. 



Spiropagurus spiriger (De Haan). 



Pagurus spiriger, De Haan, Crust. Japon., p. 206, tab. xlix. fig. 2, 1850. 

 Spiropagurus spiriger, Stimpsoii, Proc. Acad. Nat. Sci. Philad., p. 86, 1858. 



Habitat. — Torres Strait. A young male. 



Station 188, Arafura Sea; depth, 28 fathoms; bottom, green mud. An adult male. 



Station 190, Arafura Sea; depth, 49 fathoms; bottom, green mud. A female with 

 ova. 



Hong Kong, 10 fathoms. An adult female, in a shell of Pleurotonia tuherculata. 

 Gray. 



Station 208, off Manila; depth, 18 fathoms; bottom, blue mud. Two male specimens, 

 one of which is young. 



Admiralty Islands, 16 to 25 fathoms. A female with ova. 



The Challenger dredgings have increased the known area of distribution of this 

 species, jireviously recorded only from the Japanese and Chinese Seas.' Great varia- 

 tion is exhibited in the size of the piliferous lines on the chelipedes and legs, and in 

 the amount of pubescence. The inner border of the carpus in both chelipedes possesses a 

 row of spinules which vary considerably as to prominence in dillerent individuals ; the 

 piliferous lines on the upper surface of both hands are usually arranged in double series ; 

 the flagellum of the antennae is broad and flattened towards its base. In very hairy 

 individuals the piliferous lines may occur even on the upper surface of the ocular 

 peduncles and on the posterior part of the carapace, especially the branchial region 

 (where they tend to become piliferous tubercles). The ocular peduncles only extend as 

 far as the commencement of the penultimate joint of the antennal peduncle, and they are 

 slightly exceeded by the acicle ; the external prolongation of the second joint of the 

 antennal peduncle is spinulous but of no great length ; the ophthalmic scales are obtusely 

 rounded at their apices. The terminal abdominal segment is bifid, and the margin 

 spinuliferous. The female differs from the male in being of larger size, the chelipedes are 

 proportionately smaller, and no sexual appendage is present ; in the male the abdominal 

 appendages — except those of the penultimate segment — are of very small size. 



' Spiropagurus spiriger occurs also in the Indian seas, the writer having taken it lecently at Madra.s, where it is 

 apparently common in shallow water. 



