1903] On the Nemerteans of Norway. 5 



being a complete list I am well aware, as I obtained fragments of 

 a least half a dozen otlier forms undoubtedly new, but whose con- 

 dition lias rendered any adequate description impossible. Never- 

 theless several points of interest are raised by the present collection 

 in spite of its incompleteness. Between 40 and 50 species of Nemer- 

 teans are already known from the coasts of Great Britain, and the 

 majority of these are also found on the coast washed by the North 

 Sea. Of these forms only 17 have hitherto been found in the fjords, 

 the remaining 17 Norwegian species not being found on the other 

 side of the North Sea. Further, the greater number of the species 

 common to ' the two areas are only found in the comparatively 

 shallow portions of the fjords. The majority of the species from 

 the deeper parts of the fjords are unrepresented in the British area. 

 Possibly more forms common to both areas may be brought to light 

 when the deeper waters round the British coast have been more 

 carefully explored. Still Mc Intosh's observations seem to show 

 that in this part of the world at any rate many nemerteans are 

 comparatively indifferent as to the depth at which they live. Thus 

 Micrura aurantiaca 1 ) and Carinella annulata may occur in the litoral 

 zone and in depths of over 200 metres. It would seem therefore 

 that we are justified in concluding that the fjord fauna is very 

 distinct from that of the British area, almost as distinct perhaps 

 as the latter is from the Mediterranean fauna. And in this con- 

 nection it is interesting to notice that whilst the few forms yet 

 described from Greenland almost all occur both in the fjord fauna 

 and in the British fauna, two characteristic forms, Amphiporus thomp- 

 soni and DrepanopJiorus borealis, occur in the former though not in 

 the latter area. It seems not unprobable that as the Arctic fauna 

 becomes more fully known other species may be found there com- 

 mon to that region and to the deeper waters of certain of the 

 fjords. It is interesting to note that from Lyngenfjord and Pors- 

 angerfjord, where these two arctic species just mentioned were found, 

 have also afforded other typically Arctic species. 2 ) Herløfjord again, 

 where D. borealis also occurred, is almost shut off from the sea 

 and consequently little affected by the Gulf Stream. It belongs to 

 the type of fjord where, according to Noedgaard, 3 ) conditions are 

 such that we need not be greatly surprized at the appearance of 

 Arctic forms. 



x ) Mc Intosh, W. C, British Armelida, The Nemerteans 1873. P. 



2 ) Noedgaard, 0. Bergens Museums Aarbog 1899. P. 24. 



3 ) Loe. cit., p. 23. 



