50 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



coming higher and narrower and transforming into a long sharp spine after the seventh. 

 The opposing spine is as long as the width of the penultimate segment, and arises 

 from the entire dorsal surface of that segment. The terminal claw is about as long 

 as the penultimate segment, rather stout and moderately curved. 



The radials are short, with a small median tubercle on the distal border. The 

 IBrj are oblong, nearly 3 times as broad as long, with straight lateral borders which are 

 just in apposition. The IBr 2 (axillaries) are broadly pentagonal, half again as broad 

 as long. 



The 10 arms are 55 mm. long. The first 2 brachials are wedge-shaped with the 

 shorter side in, the first interiorly united for from one-half to two-thirds of their length, 

 and both slightly flattened exteriorly. The first syzygial pair (composed of brachials 

 3+4) is nearly twice as broad as long, rather longer interiorly than exteriorly. The 

 following brachials to the ninth are oblong, about twice as broad as long, after which 

 they become obliquely wedge-shaped, about as long as broad, and gradually less and 

 less obliquely wedge-shaped distally. After about the eleventh the brachials develop 

 slightly overlapping and spinous distal ends. The division series and lower brachials 

 bear a faintly indicated rounded median keel. 



Syzygies occur ordinarily between brachials 3+4, 9+10, and 14+15, and dis- 

 tally at intervals of from 7 to 11 (usually 9) muscular articulations. 



PI is about 2 mm. long, moderately stout, with 7 or 8 segments which are about 

 as long as broad. P 2 is about 3 mm. long, considerably stouter than PI, with 9-12 

 segments of which the first 2 are not quite so long as broad, the third is about as long 

 as broad, and the remainder are slightly longer than broad. The third and following 

 segments have strongly produced and spinous distal ends. PS is similar, but smaller. 

 Pt, while similar to P 3 , is about the size of PI. After the twelfth or thirteenth the 

 pinnules increase in length, reaching about 4.5 mm. distally. 



The color in alcohol is white, with a broad median line of purple on the IBr 

 series, the arms purple with a median line of white in their proximal third, the cirri 

 white with a narrow band of purple about the middle of each segment; or white, the 

 IBr series and arms with a lateral purple line which fades away distally on the arms, 

 the cirri as before; or deep violet, the cirri yellow with the usual purple band on each 

 segment. 



Notes. The preceding description is based upon the type specimen from Albatross 

 station 5153. 



The specimen from Amboina Bay has the cirri XI, 37-39, about 20 mm. long. 



The specimens from Siboga station 260 are both small, with an arm length of 40 

 mm. In one the cirri have 31-36 segments, and P 2 has 12-13 (usually 13) segments. 

 P is lacking on all the arms. In the other P a is present. 



In one of the specimens from the Danish Expedition to the Kei Islands station 54 

 the arms are 75 mm. long and the cirri have 30-32 segments. In another the arms 

 are 75 mm. long and the cirri have 24 or 25 segments. In a third the arms are 70 mm. 

 long and the cirri have 24-27 segments. In the fourth the cirri have 27 or 28 segments. 



One of the specimens from Siboga station 305 has the arms 80 mm. long and the 

 cirri IX (with a few undeveloped), 28-31, 15 mm. long. P 2 has 10 segments. The 

 other has the arms 85 mm. long. P a is absent. These specimens agree perfectly with 

 the type, even in the details of then- coloration; they are, however, slightly larger. 



