252 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The radials are very short in the median line but the anterolateral angles are 

 produced interradially forming, together with those of their neighbors, an acute 

 angle. The IBrj are almost quadrangular with obtuse anterolateral angles. There 

 is a very moderate synarthrial tubercle. The IBr 2 (axillaries) are pentagonal, as long 

 as broad, with the lateral borders converging somewhat proximally. The distal edges 

 are slightly everted and concave so that the anterior angle is acute. 



The 10 arms are about 65 mm. long. The first brachials are twice as broad as 

 long, a little longer exteriorly than interiorly, interiorly in contact hi the proximal 

 three-fourths. The second brachials are one-third again as broad as long, with the 

 first forming a small synarthrial tubercle. All the proximal brachials are slightly 

 constricted centrally, giving this part of the arm a knobby appearance. In the middle 

 and distal portions of the arms this feature becomes less and less pronounced. These 

 brachials are from half again to twice as long as broad. Syzygies occur between 

 brachials 3+4, 9+10, and 14+15, and distally at intervals of 2 muscular articula- 

 tions. 



PI is 3.5 mm. long with 10 segments. P 2 is about 5 mm. long with 12 segments. 

 PS is 3.5 mm. long with 10 segments. P 4 is usually absent. P 6 and the following 

 pinnules are present. P a is absent in 8 cases, though P b and hi most instances also 

 P are present. P d is often absent, but the following inner pinnules are present. 

 The segments of the proximal pinnules are smooth; the first is short, the second is 

 half again as long as broad, the third is twice as long as broad, the fourth is two and 

 one half times as long as broad, and the fifth and following are from 3 to 4 times as 

 long as broad and are very indistinctly thickened distally. The distal pinnules are 

 about 11 mm. long with about 25 segments of which the third-fifth, roofing the gonads, 

 are a little flattened and broadened, and the distal are about 4 times as long as broad. 

 The gonads are small, visible on the distal pinnules. 



The disk extends to the sixth brachial. 



The color in alcohol is light brownish. 



Notes. The preceding description was drawn up by Professor Gisle"n from the 

 type specimen from Dr. Mortensen's station 56. 



A specimen from Mortensen's station 57 has the cirrus-free dorsal pole of the 

 centrodorsal a little convex, 0.7 mm. in diameter. The cirri, which are arranged 

 in a double crowded row, are XXII, 18-19, about 7 mm. long, strongly curved, with 

 the longest about one-third again as long as broad. They are attached to part of a 

 sponge. The radials are distinctly visible, about four times as broad as long, laterally 

 united except in the distal fourth. The IBr, are well separated from each other. 

 The IBr 2 (axillaries) are almost hexagonal, and form an obsolete synarthrial tubercle 

 with the IBr^ The 10 arms are about 65 mm. long. On one postradial series one 

 arm has syzygies between brachials 3+4, 9 + 10, 14+15, 17+18, and 20+21, and 

 P 4 , P 6 , P a , P d , and P e are missing; the other arm has syzygies between brachials 

 3+4, 9 + 10, 14 + 15, 17 + 18, and 20+21, and P 4 , P a , P c , and P d are missing. P,, 

 P 2 , and PS are present; P 4 is almost always absent; P a is absent on eight of the ten 

 arms. P 7 and P f bear the first gonads. P t is 3 mm. long with 9 segments, and is 

 smooth and incurved over the high disk; the first segment is up to one third again as 

 long as broad, the second is half again as long as broad, the third is two and one-half 

 times as long as broad, the fourth is three times as long as broad, and the fifth is three 



