PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 453 



obscure and broadly rounded tubercles, wlu'le in others (also from Aurora station 1) 

 they are very high with the crest forked. 



[NOTES BY A.M.C.] I am selecting a lectotype from among Bell's Discovery 

 specimens. It is from Winter Quarters (McMurdo Sound) No. 6 hole, 130 fathoms 

 (238 meters), B.M. registered number 1905.3.9.81. All the arms are broken within 80 

 mm. of their length from the base, but the width at the first syzygy is 2.5 mm. and the 

 length to the second syzygy is 15.0 mm. The centrodorsal is 5.0 mm. in basal diameter 

 and 3.3 mm. high. There are about LV cirri, with up to 60 segments and up to 55 mm. 

 in length. Only one coiled P, remains intact; it has 52 segments. Pj with 21 segments 

 is 12 mm. long. For numerical details on other specimens see table 13, page 454. 



Grieg U929) notes that the largest cirri in the specimens collected by the whaler 

 Brcmsfield are about 50 mm. long and have up to 62 segments. At a length of 40 to 

 45 mm. the cirri have 52 to 54 segments. In one of the largest specimens the distance 

 between the radial and the first syzygy is 5 mm. The first pinnule is 10 mm. long with 

 36 segments. 



John (1938) gives the characters of the cirri of large specimens thus: L-LXX, 

 60-86, up to 90 mm. long. He also notes the expansion of some segments of the 

 proximal pinnules first described by Gislen in 1928, which he points out is limited to 

 the genital pinnules and is more marked in the female than the male. The figure 

 which he gives to illustrate this character in the female is taken from a Terra Nora 

 specimen of considerable size, the almost complete arms measuring 250 mm. in length. 



Young specimens.- Qauss, 385 meters, March 20, 1902: The arms are 50 mm. long 

 and the cirri are 17 mm. long with 28 to 31 segments; the apical cirri are 7 mm. long 

 with 16 segments. The carination on the proximal brachials is very long with a very 

 finely spinous crest. The dorsal surface of the proximal brachials is thickly covered 

 with fine spines which increase in size toward the carinate processes. 



Gauss, 400 meters, February 8, 1903: The arms are 50 mm. long and the cirri are 

 18 mm. long with 22 to 30 segments; the apical cirri are 4.5 mm. long with 13 segments. 

 The carination on the proximal brachials is spinelike, and is proportionately as strong 

 as in the fully grown specimens. 



Oauss, 385 meters, December 3, 1902: The arms are 40 mm. and the cirri 13 mm. 

 long. The carination on the proximal brachials is spinelike and very high. 



Gauss, 350 meters, February 7, 1903: The arms are 25 mm. long and the cirri are 

 9 mm. long with 17 segments. The brachial carination is long and very high. 



Oauss, November 29, 1902: The arms are 13 mm. long and the cirri are 4 mm. long 

 with 16 segments. The orals are still of large size. The characteristic brachial carina- 

 tion is already developed in the form of high and coarsely spinous eversions of the median 

 portion of the distal part of the proximal brachials. 



Two pentacrinoids of this species have already been described (vol. 1, part 2, pp. 

 557-559). 



Localities. Discovery; Winter Quarters, 1901-04; McMurdo Sound; No. 6 hole; 

 down to 130 fathoms (238 meters) [Bell, 1908; A. H. Clark, 1913; John, 1938] (2, B.M.). 

 Same, 227 meters [A. H. Clark, 1913; John, 1938] (2, B.M.). Same, No. 10 hole 

 [A. H. Clark, 1913; John, 1938] (5, B.M.). Same, No. ;0 hole, 232 meters [A. H. 

 Clark, 1913] (1, B.M.). Type locality. 



Terra Nova station 314; off Cape Bird Peninsula, at the entrance to McMurdo 

 Sound; 406-441 meters [Bell, 1917; A. H. Clark, 1929; John, 1938] (3, B.M.). 



