i6 



Tll. MORTENSEN, 



(Schwed. Siidpolar-Exp. 



The radial is very low, just a narrow ridge remaining in the middle, while the 

 interradial edges are rather high. The costal is low, with rounded lateral edges, not 

 in apposition laterally. Axillaries as broad as long. The shape of the primibrachs 

 and lower brachialia is shown in PI. V, Fig. i. The sides are rounded. The primi- 

 brachs and brachials are smooth, the latter only with a series of short thorns along 

 the raised outer edge; this raised edge gives the arms a serrate outline in side view 

 (Figs. 15 a — b). Syzygies on joints 3, 8, 12. 14, 16, and probably continuing on 

 every second joint towards the end of the arm. 



The first pinnule is ca. 3 — 4 mm. long, with 14 slender, somewhat 

 elongated joints, the distal edge of which is set with thorns; no terminal 

 comb (PI. V, Fig. i). P.. is exactly like Pi, but carries a genital organ. 

 P3 and P4 a little shorter and with only 9 joints; they have no ambulacral 



furrow, and thus really are oral pin- 

 nules, although carr>'ing genital or- 

 gans. The first true arm-pinnule, P5, 

 has 10 joints and is 3,5 mm. long. 

 P7 is slightly longer and has 1 1 joints; 

 this has no genital organ. All the 

 pinnules have the distal end of the 

 joints thickened and thorny (PI. V, 

 Figs. 2 — 5). No pinnules preserved 

 beyond the 7th — 8th. 



Disk naked; anal cone high, 

 situated near the oral corner of its 

 interradius. Ambulacral furrow on 

 the basal part of the arms very in- 

 conspicuous, merely a narrow, shallow 

 furrow, apparently devoid of tentacles. 

 P'arther out, from about the fourth 

 pinnule, the tentacles are distinct. 

 Sacculi few and inconspicuous on the disk and lower part of the arms, farther 

 out more numerous; on the genital pinnules they are somewhat irregularly arranged, 

 on the distal pinnules they are quite regularly arranged and fairly conspicuous. 



Side plates and cover plates are entirely absent from the ambulacral furrows, and 

 there are no spicules in the tentacles. 

 Color in alcohol whitish. 



Only a single, small, poorly preserved specimen was taken at Station 59 (53 41' S. 

 61' 10' ^V.. 137 — 150 m.) on the Burdwood bank. 



Fig. 14. 



Young cir- 

 rus of 77;. 

 tiulrix. °' I. 



Fig. 15. a. Side view of arniplates from the 



proximal part of the arm. b. Dorsal view 



of armplates from the distal part of the arm, 



of Th. 7iutrix. ^^/i. 



