154 DISCOVERY REPORTS 



There is no strong contrast between the different kinds of pinnules. In all, the distal 

 edges of the segments are faintly flared out and produced into spines ; the flare is not strong 

 enough to give the joints a swollen appearance. Pj is slender and tapers evenly from the 

 base to the tip. It is 4-5 mm. long, of 13 rounded segments all but the first two or three 

 of which are longer than broad, the distal more so than the proximal ; the distal are up 

 to three times as long as broad. Po is similar to Pj but of fewer segments and shorter, 

 of 8-g segments, about 3 mm. long. It tapers more rapidly and its distal segments are 

 more elongated. In the genital pinnules the first two segments are short, the others longer 

 than broad, the middle segments being more elongated than in the oral pinnules. P3 is 

 the first genital pinnule; it is of 8-9 segments like P2 but is slightly longer, 3-4 mm. 

 long. It bears a large egg-shaped gonad on the third to fifth segments : a testis, for the 

 specimen is a male. The genital pinnules extend to P7 or Pg (Fig. 6 d). They are all of 

 about the same number of segments as Pg , but the distal are a little longer, up to 5 mm. 

 long; their gonads are more fusiform being along the third to sixth segments. The 

 pinnules immediately beyond the genitals are about 5 mm. long and of about 12 seg- 

 ments, the first two short, the others considerably longer than broad. There are no 

 complete outer pinnules left. 



The disk is naked. Sacculi are few and inconspicuous. 



Along the pinnule ambulacra there are small rods, three to each segment, which are 

 perforated, forked or branched at the end. They are very reduced side-plates and are 

 better developed along the middle than the proximal segments. At the ends of some, 

 but not all, there are equally reduced cover-plates. Both are similar to, but more 

 reduced than, those of Phrixometra mitrix (Fig. i\e). 



The specimen is white in spirit. 



Mr A. H. Clark has kindly made for me a direct comparison of this species and 

 Emnorphometra concinna. E. aurora is considerably larger, its centrodorsal is lower and 

 broader with more numerous cirrus sockets more irregularly arranged ; its longer cirri 

 have more segments ; its radials and axillaries are longer ; the elements of its division 

 series and its brachials do not have their central portions abruptly elevated and 

 prominently spinous as in E. concinna. 



I have been able to compare E. aurora directly with E. hirsuta. E. aurora is far less 

 spinous ; the shapes of the elements of the division series and of the first two brachials 

 are quite different in the two species. The cirrus sockets of E. hirsuta are in about 

 fifteen irregular columns. 



E. aurora is easily distinguished from E. fraseri by its smaller number of cirrus 

 segments; and from E. marri by the facts that its cirrus sockets are in columns not 

 alternating rows, that P^ is not much more massive than P, , and that the segments of 

 the lower genital pinnules carrying the gonads are not expanded. 



