326 
pected either. On the other hånd it is rather easily perceived that 
some forms are restricted almost exclusively to the North Sea and 
the Skagerrack, forms which are practically never to be found in¬ 
side the Scaw; it will here, I believe, prove to be the question 
of rather stenohaline forms which require a relatively high amount 
of salinity of the water in which they live. Other species are found, 
which are indeed occurring in the North Sea and the Skagerrack, 
but at the same time enter the Kattegat reaching more or less 
southwards in this water. I have, as far as it was possible, tried 
to fix the approximate southerly limits for these species. Some are 
only to be found in the northern part of the Kattegat, others are 
proceeding until the Southern part of this water and some few 
enter the Sound and the Belts. Finally there are species, which 
from the Kattegat pass through the Sound and the Belts and enter 
the Baltic with its low salinity, where they are to be found more 
or less easterly. 
Only a few species enter the Baltic; according to the newly 
published list of Thulin 13 species in all, and of these none 
are endemic of this water. Of these thirteen species only five 
are represented in the material of the “Dana". It seems mostly 
to be euryhaline forms, some of which are euryhaline to such 
a degree, that they can be found practically anywhere in our 
waters without regard to the salinity if only the circumstances are 
otherwise suitable to them. Of such forms I shall here only name 
Terebellides Stroemi and presumably Scoloplos armiger. The same 
possibly also holds good for Neoamphitrite figulus. All of these 
three species are rather common in the Baltic; the Terebellides 
Stroemi is to be found as far easterly as the entrance of the Gulf 
of Finland. 
On the following list are to be seen the stations of the “Dana" 
from which Polychæta are recorded. I have put down the different 
depths, bottom-temperature, salinity at the bottom and the nature 
of the bottom. I beg to thank on this occasion Dr. A. C. Johan¬ 
sen for the courtesy with which he placed at my disposal the jour¬ 
nals of the “Dana" concerning the cruises in 1922—23. The ma¬ 
terial originating from other sources is not listed. 
When examining this list, it will easily be observed, that there 
is a great difference among the various regions as regards the quan- 
tity of species of Polychæta. Some regions are very poor, others 
are to be pointed out as rich. Poor is for instance the Baltic; and 
if we look at the list of species for the stations from this water 
