194 DISCOVERY REPORTS 



As in N. mortenseni (see below) the oral pinnules are not entirely free. Pj and P3 are 

 attached to the disk by their first three to five segments ; the first three to four segments 

 of the other oral pinnules are attached by a web to the tissues of the arm. In all but the 

 smallest specimens Pj is of 11 -16 segments, 6-10 mm. long; Pa of 11-18 and P3 of 

 12-20 segments, each 6-1 1 mm. long. In the smallest specimens the oral pinnules are 

 of slightly fewer segments. The first genital pinnule is P3 or P4 ; the last may in large 

 specimens be so far out as P27 . The outer pinnules may be up to 20 mm. in length. 



The syzygies are more irregularly arranged than Mortensen records. The first is 

 abnormally placed on certain of the arms of seven specimens: on one arm it is 2 + 3, 

 on six 4 + 5, on two 8+9, and on one so far out as 18 + 19. On arms where the first 

 syzygy is normally placed there are examples of the second occurring between almost 

 every pair of brachials between the fifth and the twenty-second. There are three ex- 

 amples of the first syzygial pair (3 + 4) being immediately followed by another, 5 + 6, 

 and in each the pinnules are abnormal. Two are on arms of the specimens from St. 1948. 

 In one the epizygal of the first pair, in the other the epizygal of each pair, bears two 

 pinnules, one on either side. The third example is on an arm of the Ross Sea specimen 

 (St. 1658) where the first three syzygial pairs are 3 + 4, 5 + 6, 7 + 8; the epizygal of 

 the second pair bears two pinnules, one on either side. 



The sacculi are usually inconspicuous but in some specimens are of a dark brown 

 colour. 



Some of the embryos are bigger than those seen by Mortensen, as much as 2 mm. 

 long, but all seem to be at the same stage of development. Mortensen found no penta- 

 crinoids but suggested that they may attach themselves to the walls of the marsupia as 

 in Phrixometra iiutrix. There is none so attached to the females of this collection and 

 I do not think they have this habit, for from Sts. 170 and 175 come twenty pentacrinoid 

 larvae, one attached to the cirrus of an adult Notocrmus vtrilis, the remainder to foreign 

 bodies, which are certainly of A'^. virilis. They do not include any of the younger, pre- 

 brachial stages. The series is described on pp. 210-219. 



Distribution. The species appears to be circumpolar in distribution for it is known 

 from the South American, the Indian Ocean and the Ross Sea sectors of the Antarctic. 

 It has been taken from depths between 80 and 650 m. 



Notocrinus mortenseni n.sp. (Plate VI, fig. 2) 



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

 DLH. Bottom: rock. Two specimens. 



St. 187. 18. iii. 27. Neumayr Channel, Palmer Archipelago. 64° 48' 30" S, 63° 31' 30" W. 

 259-354 m. Gear OTL. Bottom: mud. One specimen. 



St. 190. 24. iii. 27. Bismarck Strait, Palmer Archipelago, 64° 56' S, 65° 35' W. 315 m. Gear 

 DLH. Bottom: mud and rock. Three specimens. 130-100 m. Gear DLH, NRL. Bottom: mud, 

 stones and rock. One specimen. 93-130 m. Gear DLH, NRL. Bottom: mud, stones and rock. 

 Two specimens. 



St. 1948. 4. i. 37. East of Clarence Island. 60" 494' S, 52° 40' W. 490-610 m. Gear DRR. 

 One specimen. 



