NOTOCRINIDAE 



193 



Family NOTOCRINIDAE 



Genus Notocrinus Mortensen 



Notocrinus virilis Mortensen (Plate VI, fig. i) 



Mortensen, 1918, pp. 2-10, figs. 1-5, pi. i, figs. 1-5, pi. ii, figs. 1-4, pis. iii-iv. 1920, pp. 49-53, 

 fig. 7, pis. xxiv-xxvi. Clark, 1921, many references, pi. 49, figs. 1329-30, pi. 55, figs. 1349-52. 

 Clark, 1929, p. 664. Grieg, 1929 a, p. 5. Clark, 1937, p. 16. 



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

 DLH. Bottom: rock. Seventeen specimens. 



St. 175. 2. iii. 27. Bransfield Strait, South Shetlands. 63° 17' 20" S, 59° 48' 15" W. 200 m. 

 Gear DLH. Bottom: mud, stones and gravel. Seven specimens. 



St. 1658. 26.1.36. Off Franklin Island, Ross Sea. 76° 09-6' S, 168° 40' E. 520 m. Gear DRR. 

 One specimen. 



St. 1948. 4. i. 37. East of Clarence Island. 60° 49-4' S, 52° 40' W. 490-610 m. Gear DRR. 

 One specimen. 



All but one of the twenty-six specimens of this robust species are in good condition. 

 Six have arm lengths of between 100 and 130 mm., 

 nine of between 80 and 95 mm., five of between 60 and 

 75 mm., four of between 40 and 55 mm., and the 

 smallest is 28 mm. long. The largest are, I think, bigger 

 than any of the Swedish Expedition's collection and it 

 is perhaps for that reason that I have to make some of 

 the small additions that follow to Mortensen's full 

 description. 



The radial may be longer than the costal as in Mor- 

 tensen's figure (1918, pi. ii, fig. i), or of the same length 

 or shorter. 



The examination of the cirri of the specimens of this 

 collection leads to the following numerical description, 

 wider than Mortensen's, of the cirri : XXI-XLII, 36-76. 

 There is a distinct and sharp change in colour between „. ., . ... ... 



'^ ^ r'lg. 19. I\otocrimis virilis. a, distal part 



the proximal and distal cirrus segments: the first eight ofcirms from specimen from Graham 

 to thirteen are of a deep straw colour which may be 

 tinged with red; those beyond are nearly white. 



There are in the Museum collection two specimens of this species, from the Terra 

 Nova station 295 (348 m.) in the Ross Sea, which, unlike that recorded by Clark (1929, 

 p. 664) from the same region, retain their cirri. They, and those of the single specimen 

 of the present collection which comes from the Ross Sea, differ from those of typical 

 specimens from the Falkland Sector of the Antarctic in that the dorsal prominences of 

 the distal segments are more strongly developed and spine-like, as a comparison of 

 a and b in Fig. 19 will show. Some of the cirri of large Falkland Sector specimens may, 

 however, have dorsal prominences nearly as big as those of Ross Sea specimens. 



Land region, x 5. b, same from speci- 

 men from Ross Sea, x 5. 



