2IO DISCOVERY REPORTS 



Other oral plates are pushed farther distally than in the younger specimens; their 

 proximal edges are level with those of the first brachial. 



The costals and axillaries are as wide as the radials and of the shapes shown in Fig. 20^. 

 The arms are of 22-24 brachials with pinnules arising from the tenth and succeeding 

 brachials. The longest pinnules are of ten or more segments. There are side-plates and 

 a few sacculi along the arms. 



15. Length of crown ca. 11 mm. (Fig. 22/). 



This is a far bigger and older specimen than the last (No. 14). 



The stem is of 32 columnals and a very large and lobed terminal plate. The first 

 columnal is considerably longer than in No. 14, and tapers somewhat distally. It bears 

 three whorls of cirri. The largest is a radial whorl arising from the distal half of the 

 columnal, one in each radius ; the longest are of 27 segments and extend as far as the 

 seventh brachial. They terminate in claws and their penultimate segments carry small 

 opposing spines. A whorl of much smaller cirri arises interradially from half-way along 

 the columnal. There are five cirri in this whorl, one in each of three interradii, two in the 

 fourth and none in the fifth which is contiguous with it. The beginnings of a third, 

 radial, whorl arise from the proximal border of the columnal. 



The second columnal is short and discoidal and slightly wider than the tapered end 

 of the first ; its proximal border is incised opposite each of the large radial cirri, so deeply 

 opposite some cirri as to extend for the length of the segment and so cut its periphery 

 into lobes. The third columnal is short and discoidal and very slightly narrower than 

 the second. The fourth and fifth are irregular and narrower and longer. The remainder 

 of the columnal is similar to the same parts of those of the stages already described. 



The basal plates are very reduced ; in the radial mid-line they appear to be less than 

 one-sixth as long as the radials. The radials are long and in close contact with one 

 another. The costals and axillaries are as wide as the radials. The arms are too closely 

 pressed together for the oral plates or the radianal to be seen. 



The arms are of about 30 brachials. Syzygies occur between brachials 3 + 4, 9 + 10 

 or 10+ II, 13 + 14, 18+ 19. Long pinnules or 12 or more segments arise from the 

 tenth and succeeding brachials. The beginnings of the first pinnules (Pj) are present 

 on the second brachials. 



There are fairly regularly arranged small dark sacculi along the arms and small side- 

 plates along the arm ambulacra. There are small side-plates, one or two to each segment, 

 along the pinnule ambulacra and numerous spicules in the tentacles. A few of the 

 spicules are nearly smooth but most are strongly thorny and some are branched. The 

 side-plates are not unlike, and the spicules resemble, those of adult Isometra hordea. 



Pentacrinoid larvae of Notocrinus virilis Mortensen 



St. 170. 23. ii. 27. Off Cape Bowles, Clarence Island. 61° 25' 30" S, 53° 46' W. 342 m. Gear 

 DLH. Bottom: rock. Eighteen specimens (Nos. 1-7, 10-20). 



St. 175. 2. iii. 27. Bransfield Strait. 63° 17' 20", 59° 48' 15" W. 200 m. Gear DLH. Bottom: 

 mud, stones and gravel. Two specimens (Nos. 8 and 9). 



