114 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



following the first few oblong ones have rather prominent distal ends thickly set 

 with very fine spines, and a longitudinally striate dorsal surface. 



The first syzygy is between brachials 1+2, except on arms springing directly 

 from a IBr axillary, where it is between brachials 3+4. If the first syzygy is be- 

 tween brachials 1+2, brachials 3 + 4 may also be syzygially united The next syzygy 

 is somewhere between brachials 11+12 to 15 + 16, usually about brachials 13 + 14. 

 The distal intersyzygial interval is usually 3, sometimes 4, muscular articulations. 



PI is slender, from 15 to 17 mm. in length, composed of 50 segments which are 

 about as long as broad; the terminal comb has 15-17 narrow, triangular, slightly 

 recurved teeth wh'ch reach a height of from one-half to almost the whole width of 

 the segments. P 2 is similar, about 12 mm. long. P 3 is similar, about 9 mm. long. 

 P 4 is similar to P 3 and only slightly shorter. P 5 and the following pinnules are with- 

 out combs, slightly stouter than those preceding and much less flagellate, about 6 mm. 

 long. The 2 basal segments of the first 4 pinnules on each side of the arm are more 

 or less carinate. The distal pinnules are 7 mm. long. 



The mouth is radial. The disk is naked, 12 mm. in diameter. 



The color in alcohol is uniform dark reddish brown, or dark reddish brown 

 mottled with patches of yellowish green. 



Notes. The description of this species as given covers both the type specimen 

 from Challenger station 186 in the British Museum and the specimen from Bowen 

 in the Copenhagen Museum. The two are almost identical. That from Bowen has 

 19 arms 80 mm. long, while the type has 20 arms 70 mm. long; the cirri in the speci- 

 men from Bowen are XVIII, 16-17, and in the type are somewhat larger, XXV- 

 XXXV, about 20. 



The specimen from Salomon has 26 arms 85 mm. long; the cirri are XXI, 15-18 

 (usually 17 or 18). When compared directly with the type specimen this is found 

 to differ only in having a greater number of arms. All of the IIIBr series are devel- 

 oped externally. 



The example from Hulule has 17 arms. 



The specimen from Ceylon has 26 arms, most of which are in process of regen- 

 eration. According to Reichensperger the details agree well with those of the 

 specimen from Bowen. The centrodorsal is of medium size, discoidal, and some- 

 what prominent. The cirri are XVII, 15-18; the middle segments are much longer 

 than broad. The surface of the first 7-9 segments is rough and dull, but the seg- 

 ments following have a porcelainlike polished surface, which usually begins in the 

 middle of one of the segments (the transition segment). The arm length scarcely 

 exceeds 75 mm. The first 2 brachials are always united by syzygy. The 2 basal 

 segments of the first 3 or 4 pinnules, especially on the outer side of the arms, are 

 sharply carinate. P 2 is usually the stoutest pinnule. 



The specimen from Siboga Station 96 is quite typical. There are 16 arms, and 

 in addition a IIBr series ending in a pair of pinnules. The arms are 65 mm. long. 

 The centrodorsal is thin discoidal with the dorsal pole fiat, 3 mm. in diameter. The 

 cirri are slender, XXI, 17-18, from 9 to 11 mm. long; the seventh, or more rarely the 

 eighth, is a transition segment. 



Doctor Mortensen's specimen from off Jolo had apparently 20 arms; the longest 

 cirri have 18-19 segments. 



