Bryozoa of the Canadian Arctic Expedition, 1913-18 



By Raymond C. Osbukn 



From the Kara sea westward to the American archipelago the marine 

 bryozoa are perhaps as well known as in any other part of the world. Beyond 

 these limits we have known practically nothing of the circumpolar distribution 

 of this group. The bryozoan studies of Hincks (1884) and Robertson (1900) 

 on the British Columbian and southern Alaskan species have indicated a simi- 

 larity to the northern Atlantic fauna and the supposition has been general that 

 most of the arctic bryozoa are circumpolar in distribution. 



The study of the bryzoan collections made by the Canadian Arctic Expe- 

 dition, 1913-18, confirms this belief. Though this material contains only 48 

 species, and is therefore probably not half of the complete list that might be 

 found in the region covered by the survey, all those obtained have previously 

 been taken elsewhere and for the most part are well distributed in the arctic 

 waters thus far explored. 



The region collected over extends from Bernard harbour, on Dolphin and 

 Union strait, westward to Grantley harbour, on Bering strait, or, from about 

 115 to 165 degrees west longitude. 



To make the series more complete for arctic America, I have included in 

 the report the species taken farther eastward in Hudson bay and strait by the 

 Diana and Neptune expeditions in the years 1897 and 1903-1904 respectively. 



The bryozoa of Greenland have been quite thoroughly studied,* and 

 Nordgaard (1906) has reported on 77 species taken in the region of North 

 Devon island, just west of Baffin bay. 



Our knowledge of the arctic bryozoa may be said to have made a partial 

 advance some 80 degrees of longitude farther westward by the work of the 

 Canadian Arctic Expedition, 1913-18. The collections are too small and the 

 area covered too limited to yield more than a partial view of the distribution 

 in this region. 



There still remains a vast region north of Siberia from Bering strait to the 

 Kara sea, 165 degrees west longitude to 70 degrees east longitude, or nearly a 

 third of the circumpolar area, in which the bryozoan fauna is quite unknown 

 to us as yet. There can, however, be little doubt that the species will be found 

 to be very similar to those of other arctic waters. 



Nordgaard (1917, p, 90) has indicated that "there seems to be some differ- 

 ence between the arctic region of the Atlantic and that of the Pacific." How- 

 ever, it may be that when the unexplored regions of the Arctic ocean have been 

 studied and the regions in which but little investigation has been made, are 

 better known, we may come to the conclusion that there is no fundamental 

 difference. It' is probably to be expected that certain species may occur in 

 limited regions of the arctic seas, due to recent distribution froni more southerly 

 waters or for some, at present, unknown reason, but the conditions of life in 

 the waters about the north pole and for an average of 20 degrees to the south- 

 ward are so constant that a fairly uniform distribution of species' is to be ex- 



*For a digest of the work done and a complete list of the 186 species and varieties known from 



InnH RP.R Oshlim. 1919. 



Greenland, see Osbum, 1919 



3d 

 49889— li 



