2 45 



b 1 centrodorsal sharply conical with straight sides, nearly or quite as long 



as broad at the base Fariometra 



b 3 centrodorsal less sharply conical, with rounded sides, or hemispherical, 

 and lower 



c 1 all the brachials have strongly produced and very spinous edges ; 

 P x very slender and delicate, markedly longer than P 3 , with the 

 outer segments very greatly elongated with overlapping and spinous 

 distal ends (from southern Japan, the Hawaiian and 

 Philippine Islands westward to Cape Comorin, the nee 

 southwestward t o between M a r i o n I s 1 a n d and the 

 C r o z e t s ; from the Ba)- of B i s c a y nortliward t o 5 4° 1 7' 

 N. lat. , and from B r a z i 1 northward t o the Newfound- 



land banks; 24S — 2926 Me tres) Trichometra 



c 2 the brachials do not have strongly produced and very spinous 

 distal ends ; at most the distal edges of the outer brachials are 

 bordered with fine spines 



d 1 Pj much elongated, between two and three times as long as P,, 

 composed of 30 — 40 segments of which a few of the basal are 

 short, the following becoming slender and greatly elongated 

 (Are tic Ocean from western Greenland to the Kara 

 Sea, and southward to Portugal and Chesapeake 

 Bay, and a 1 s o in the v i c i n i t y of Marion I s 1 a n d , 

 southeast of South Africa; 18 — 1800 Metres) . . . . Hathrometra 

 d' 3 Pj the same length as, longer than, or shorter than, P„; but if 

 longer never more than slightly so, and with not more than 

 20 segments 



e 1 cirri with 20 — 30 relatively short segments of which the 

 last six to thirteen are only very slightly, if at all, longer 

 than broad 



f 1 pinnules not especially long-, distal pinnules the same length 

 as the proximal pinnules; P 2 resembling P s and the following 

 pinnules, slightly longer and stouter than Pj with somewhat 

 fewer segments which are proportionately longer; P„ may 

 bear a gonad, though these usually begin on P 3 ; arms 

 25 mm. to 60 mm. long; cirri L — LX, 21 — 30 (Kei 

 and Meangis Islands, and southern Celebes; 



204—1158 Metres) Nepiometra 



f- pinnules very long; distal pinnules not so long as the 

 proximal pinnules; P very slightly shorter than P, but 

 similar to it, with about iS elongated segments; following 

 pinnules similar; arms about 20 mm. long; cirri about 



