244 DISCOVERY REPORTS 



(a) Phascolosoma eremita Sars var. aiistrale Benham. 



Commonwealth Bay. Benham (1922, p. 17). 

 {a) Phascolosoma intermedium Southern. 



Commonweakh Bay. Stephen, B.A.N. Z.A.R.E.i Rep. (in the Press). 



(a) Phascolion strofnbi (Montagu). 



(b) Phascolosoma benhami Stephen. 



Off Kemp Island; off AdeUe Land. Stephen, B.A.N.Z.A.R.E. Rep. (in the 

 Press). 



(c) Phascolosoma anderssoni TheeL 

 [c) Phascolosoma charcoti HerubeL 



Port Charcot. Herubel (1908, p. 2). 

 (c) Phascolosoma nordenskjoldi Theel. 

 {c) Phascolosoma ohlini Theel. 

 (c) Phascolosoma pudicum Selenka. 



Kerguelen. Selenka (1885, p. 11); Stephen, B.A.N.Z.A.R.E. Rep. (in the Press), 

 (c) Phascolosoma mawsoni Benham. 



Commonwealth Bay. Benham (1922, p. 13). 



Off Enderby Land : off Kemp Land. Stephen, B.A.N.Z.A.R.E. Rep. (in the 

 Press). 

 {c) Phascolion Intense Selenka. 



Southern Indian Ocean. 53° 55' S, 108° 35' E; 62° 26' S, 95° 44' E. Selenka 

 (1885, p. 16). 

 Priapulidae. 



{a) Priapulns caudatus Lamarck var. tiiberciilato-spinosiis Baird. 



{a) Priapulus bicaudatus Koren and Danielssen var. australis de Guerne. 



Patagonia; South Shetlands. De Guerne (1888, p. 13). 

 (c) Priapidus horridiis Theel. 



Coast of Uruguay. Theel (191 1, p. 24). 

 Thus of the twenty-three species listed, ten come under category {a) and two under 

 [b) ; that is, half are either northern species or very closely related to them. While this 

 phenomenon of bipolarity is well known and is seen in other groups of animals, it would 

 appear, when all the records are examined, to be as well shown in these groups as any. 

 The question of bipolarity has been discussed by several authors and more than one 

 theory put forward to account for the facts. It seems too early as yet to try to theorize, 

 especially in view of the considerable additions made by the B.A.N.Z.A.R.E. and 

 Discovery Expeditions. Also, in spite of the considerable surveys made, several species 

 are represented by only one or two specimens. Intensive work would almost certainly 

 secure many more records which might show a very different picture. One fact, how- 

 ever, seems to stand out and may represent a real condition, namely, that in the Ant- 

 arctic most of these bipolar species seem to be confined to the South American quadrant. 

 1 British, Australian and New Zealand Antarctic Research Expedition. 



