I' is 7.5 mm. long with 16 segments, resembling 1', but proportionately stouter; the 

 distal ■ the third and following segments are slightly produced and finely spinous ; as 



in P, the dorsal edge of th( 1 and third segments is slightly thickened. 



1' is 1 2 mm. t<> 13 mm. long with :: segments, resembling I' bul proportionately stouter. 



P i> 5.0 mm 5 mm. long with 14 segments, similar in size to P but with the 



distal segments ver) slightly shorter. 



1' is 6 mm. long with 15 segments, slightly stouter than I', and not tapering so rapidly. 



i ie distal pinnules are 6.5 mm. long with 16 segments, very slender, the segments 

 beyond the two basal much 1 ted. 



Thi ir in spirits is deep purple, banded with yellowish at the articulations; the 



r pinnu yellowish. 



The specimens from Stats. 70' and 99, and the smaller from Stat. 96, have an arm 

 th of between 25 mm. and 30 mm.; that from Maumeri is large, but badly broken. 



Iridometra A. II. Clark. 

 Key to the Species of the Gemis Iridometra. 



a ('in-i not slender. the longest segments rarely more than four times as long as 

 the median diameter, with the articulations only very slightly enlarged; Pj and 

 1' with 16 — 19 segments; I', slighdy longer than 1', 



b 1 Pj, 1' and 1' of approximately the same length (P s slightly longer than I' . 



which is slightly longer than P,), with iS — 20 segments; cirri XL, 12 — 17 



irely more than 15), 10 mm. to 12 mm. long; arms 35 mm. to 60 mm. 



long (sou-t hern Japan; 23 — 192 [^250] Me tres) adrestine 



b 1', and 1', of approximately the same length (P„ slightly longer than l\), 

 with 16 segments, but P shorter with 13 segments; cirri XXX -L, 15 — 19 

 (usually 16 — 18), 10 mm. to 14 mm. long; arms about 50 mm. long (China 



- a, n e a r Hong K on g ; 158 — 180 Metres) melpomene 



a < irri exceedingly slender with greatly elongated segments of which the proximal 

 are at least six times as long as the median diameter, with greatly swollen 

 articulations; P, and P. similar, the latter usually slightly shorter than the former, 

 with 1 1 — 13 segments; P smaller, with 8 — 9 segments, arms 40 mm. — 50 mm. 

 long (Philippine Islands; 62 — 140 Metres) exquisita 



1. Iridometra adrestine (A. 11. Clark). 



A. II. CLARK. Smithsonian Miscellaneous Collections (Quarterly Issue), vol. 50, 1907, part 3, 



p. 340 Anti den adrestine); p. 341 \.\ntedon uiinitta). 



2. Iridometra melpomene A. 11. Clark. 



A. H. CLARK. Proc. U.S. National Museum, vol. 39, 191 1, p. 359 [Iridometra melpomene). 

 This species is infested with a curious amphipod parasite which bores into the disk, 



