252 Т"' MOHTENSEN. 



stalk-joints appear to afford good characters for distinguishing the 

 species — at least this holds good for the species treated here. 



Aste ro idea. 



3. Bathybiaster vexillifer (Wyv. Thomson). 

 PI. XIV, Figs. 2, 5. 1^1. XVII, Figs. 8, 14. 



Archaster vexillifer Wj'v. Tho mson. 1873. The Depths of the Sea. 



p. 150. Fig. 25. 



Bathybiaster pallidas Danielssen & Koren. 1884. Norske Nord- 

 havs Expedition. Asteroidea. p. 89. PI. XIV. 

 Figs. 1—15. 



Ilyaster mirabilis Danielssen & Koren. Ibid. p. 100. PI. VII. 



Figs. 15—19. 



Bathybiaster vexillifer F. Je ffr. Bell. 1891. Observations on a rare 



Starfish, Bathybiaster vexillifer. Proc. Zool. 

 Soc. p. 228. PI. XXIII-XXIV. 



— pallidas H. Ludwig. 1900. Arktische Seesterne. Fauna 



Arctica. p. 455. 



— vexillifer J. Grieg. 1906. Echinodermen von . . . "Mi- 



chael Sars" 1900—1903. 111. Asteroidea. p. 14. 

 PI. I. Fig. 1. 



— — R. Ko eh 1er. 1909, Echinodermes . . . Princ. 



Alice. Monaco. Fasc. XXXIV. Pi. XI. Figs. 8— 10. 

 Station 98. (77^ N. 18V/l'° W.) 304 m. 1 specimen. 



In the "Michael Sars"-Asteroidea Grieg has given some excel- 

 lent critical remarks on this species, showing a. o. that the "vexil- 

 lum", the peculiar adambulacral appendage which has given rise to 

 the name of the species, is not a kind of pedicellaria, as was main- 

 tained by Danielssen & Koren in their description oï Bathybiaster 

 pallidas, which is really the same species as B. vexillifer. V^hile I 

 quite agree with Grieg that the "vexillum" is by no means a kind 

 of pedicellaria, I find that there is still some error in his conception 

 of this appendage, and I therefore think it not inappropriate to give 

 some remarks tending to show the real character of this somewhat 

 mysterious "vexillum". 



„An den innersten Adambulacralstachel, den Eckstachel, befe- 

 stigt, ragt „das Vexillum" mit dem freien Ende über die Ambulacral- 

 furche" . . . „Das untere Ende, was mit kurzen Ligamenten an dem 

 Adambulacralstachel befestigt ist, ist quer abgeschitten", says Grieg 

 (Op. cit. p. 17). In the same way Bell writes (Op. cit. p. 229): "Atta- 

 ched to the spine al the angle is a blunt movable spine-like process, 



