POLYCH^TA-BENHAM. 67 



The absence of any dorsal cirrus above the first chsetigerous lobe serves to 

 differentiate the species. 



The dorsal cirri along the middle and hinder portions of the body are coloured 

 reddish brown by little spots of pigment, and similar though smaller spots occur in 

 groups along the back. 



Locality. 



Commonwealth Bay. No data. 



Distribution. Port Charcot (Gravier), Kaiser Wilhelm II Land (Ehlers). 



Sub-family LOPADORHYNCHIN.E. 



Genus PELAGOBIA Greef. 

 PELAGOBIA VIGUIERI Gravier. 

 Gravier (1911), p. 62, pi. II, figs. 22-25. 



(Plate 7, figs. 58-60.) 



Numerous individuals of this small pelagic worm were obtained in tow-netting 

 in January, 1914, in depths from 45 to 100 fathoms, when the water was far below 

 freezing point. One vial is marked " Temp. 0.5 C."; another " Partly ice." Mixed 

 with them was Tamopteris septentrionalis . 



The length varies from 5-12 mm.; the head is followed by 21-25 segments, 

 the larger ones being sexually mature, containing eggs or sperm morulae. 



Gravier's account, founded on only three specimens, agrees precisely with the 

 present worms, but for one apparent omission. He has overlooked the existence in 

 the long metastomial cirri of a chitinous supporting axis. 



He correctly describes the first segment, which immediately follows the " head," 

 as possessing on each side a very long dorsal and ventral cirrus, separated by a smaU 

 bundle of compound chaetse, such as occur throughout the worm. Each cirrus presents 

 a swollen base, and has a much thickened cuticle on its posterior face (figs. 59-60). 

 This cirrus is traversed nearly throughout its length by a delicate chitinous aciculum 

 or thread of chitin. It starts at the apex of the cirrus, and just before the swelling is 

 reached it tapers to a very fine point. 



This axial support is so evident in specimens mounted in glycerine, as well as in 

 balsam, that it is astonishing that no mention of it is made by Gravier. 



Locality. 



Commonwealth Bay, 45 faths., 50 faths., 100 faths. 



Distribution. Lat. 69 15' South : long. 108 5' West, at a depth of 950 metres. 



83892 H 



