662 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



ambulacral furrow. P 5 is 3.5 mm. long with 10 segments. P 7 is slightly longer with 

 1 1 segments, and has no gonad. None of the pinnules beyond P 7 or P 8 are preserved. 

 All of the pinnules have the distal ends of the segments thickened and spiny. 



There are no calcareous deposits along the ambulacral grooves, nor in the tentacles. 



The disk is naked ; the anal cone is high, situated near the oral angle of the inter- 

 radial area. 



The ambulacral furrows on the basal part of the arms are very inconspicuous, 

 merely a narrow shallow groove apparently devoid of tentacles. Further out, from 

 about P 4 , the tentacles are distinct. 



The sacculi are few and inconspicuous on the disk and lower part of the arms, 

 becoming more numerous further out. On the genital pinnules they are somewhat 

 irregularly arranged, but on the distal pinnules they are quite regular and fairly 

 conspicuous. 



[NOTES BY A.M.C.] A male specimen taken by the Discovery Investigations in 

 the Bransfield Strait, which is south of the Antarctic convergence, was ascribed to this 

 species by Dr. Dilwyn John. The type specimen of nutrix was from the Burdwood 

 Bank, which is not an antarctic locality and which has a fauna distinct in the main 

 from that of the South Shetlands Bransfield Strait area. 



The Bransfield Strait specimen has most of the cirri present and complete but the 

 arms are badly broken. 



The centrodorsal is low and rounded with a rather large, slightly rough dorsal pole. 

 The cirrus sockets are closely set and indistinctly arranged in columns. 



The cirri are about XLVII, 12-18. After the first two segments, which are very 

 short, the segments are longer than broad, though the distal are only slightly so. 

 The third to about the seventh are the longest; they are slightly constricted in the 

 middle, more strongly on the dorsal than on the ventral side. The following segments 

 are wider at then* distal ends than proximally but no dorsal spines are developed. The 

 distal segments are noticeably wider than the middle segments. The terminal claw 

 is strong but the opposing spine is weak. 



The IBri are more conspicuously narrowed distally than in the type specimen and 

 are also more deeply incised by the IBr 2 . The distal edges of the brachials beyond 

 the first syzygy are flared and thorny. 



The first two segments of all the pinnules are short; the rest are elongated with 

 their distal ends flared and thorny. PI has 14 segments, as in the type, and is about 5 

 mm. long. P 2 is a genital pinnule. None is complete, the longest having 9 segments 

 measuring about 4 mm. Dr. John estimated that there were probably about 14 segments 

 as in PL The large fusiform gonad lies along the third to sixth segments. P 3 is of 10 

 segments and 4 to 5 mm. long. P 6 with 11 segments is the same length. It has an 

 ambulacral furrow. The outer pinnules have about 12 segments. 



The disk is naked, the anal cone high. Sacculi are conspicuous, irregularly 

 arranged on the lower part of the arms and the genital pinnules, regularly arranged 

 on the outer pinnules. 



Simple rodlike side and cover plates are present to the number of three pairs 

 along each middle segment of the outer pinnules. No such plates were found in the 

 type. 



