6 c Canadian Arctic Expedition, 1913-18 



collected, is a very characteristic and common invertebrate in about 5 fathoms 

 of water on a bottom of sandy mud in the vicinity of Bernard harbour, Dolphin 

 and Union strait. There is here a rich algal flora consisting of Laminaria and 

 other Fucoidese, Delesseria and other Florideae, green-thread algae, etc., con- 

 stituting a Laminaria zone, and the dominating dark-brown colour of the algae 

 influences the colour of the holothurians, some of which are dorsally, or even 

 entirely, dark brown instead of the normal and typical transparent flesh-colour. 

 Many of the specimens collected contained well-developed embryos. 



ECHINODERMA ASTRORADIATA. 



Class OPHIUROIDEA. 



Order Chilophiurida. 



Family OPHIOLEPIDIDiE. 



Stegophiura nodosa (Liitken) 



Station 20g. Port Clarence, Alaska; 2-3 fathoms; sandy grey mud with 

 algae (thread algae, Laminaria, etc.); August 4, 1913. 



Twelve specimens, of which the largest has the disc 10 mm. in diameter and 

 the arms 25 mm. long, and the smallest has the disc 3 mm. in diameter and the 

 arms 5-5 mm. long. 



Mr. Johansen records that in life these were red dorsally. 



Station 23. Northeast of Icy cape, Alaska (70° 24' N., 161° 25' W.); 

 9-10 fathoms; mud and pebbles; August 19, 1913. 



Four specimens, of which the largest is 10 mm. across the disc, with arms 

 16 mm. long. 



Station 41c. Outer harbour at Bernard harbour, Northwest Territories; 

 3-8 fathoms; grey mud with Laminaria and Delesseria; July 28, 1915. 



Ten specimens; the largest has the disc 9 mm. in diameter and the arms 

 19 mm. long, and the smallest has the disc 1-7 mm. in diameter and the arms 

 2-6 mm. long. 



Mr. Johansen states that in life these were rose colour, darkest dorsally, 

 with the dorsal surface of the disc purplish. 



Ophiozea robusta (Ayres) 



Station 43c. West of Cockburn point, Dolphin and Union strait. Northwest 

 Territories; 20-30 metres; grey mud, with many stones and algae {Laminaria, 

 Delesseria, smd Lithothamnion) ; September 14, 1915. 



Ten specimens, of which the largest has the disc 11 mm. in diameter; 

 another has the disc 10 mm. in diameter and the arms 41 mm. long. 



These vary much in colour, some being as dark, with as strongly contrasting 

 white markings, as any from Kamchatka (maculata of Ludwig), while others 

 are an almost uniform brownish grey. 



Mr. Johansen writes that in life these showed a faint to strong contrast 

 of black and grey spots and bands, and that the colours are well preserved in 

 alcohol. 



Ophiocten sericeum (Forbes) 



Station 43a. Off Cockburn point. Dolphin and Union strait; about 50 

 fathoms; sandy mud with pebbles, and no algae; September 13, 1915. 



