ß44 Frits Johansen. 



fourth region, namely, a region with mud and sand bottom with 

 a few red algae (most numerous when stones are present). And at 

 a depth of over ca. 100 m we meet with the mud and sand bottom 

 with or without stones and without vegetation; this region has 

 already been mentioned p. 642. 



Comparing the conditions described, we see that the various 

 algal vegetations on the hard bottom are as a rule more sharply 

 marked from one another and have a less extension than those on 

 the soft bottom. These characteristics in conjunction with the 

 qualitative differences of the vegetation, the copious or sparse growth 

 (sometimes quite lacking), the presence of fixed or loose-lying algae, 

 are certainly produced partly by the ice, partly by the currents at 

 the different places; the places with strong currents are preferred 

 by special algae (Laminaria), and thus these occur especially on the 

 hard bottom, whilst the soft bottom has most algae when loose 

 stones are abundant or when the water is sufficiently deep. 



It would seem natural also, along with this sketch of the algal 

 vegetation, to give an account of the invertebrates occurring in 

 the diff"erent regions. As the collections brought home have only 

 partly been worked up, however, I must postpone this to a later 

 occasion. So much may be said, however, that just as there is a 

 distinct difference in the animal forms which live on hard bottom 

 (characterized by larger Mollusca, a few Crustacea, Caprella arcturus 

 and masses of Hydroids and Bryozoa) and the fauna living on soft 

 bottom (small Mollusca, numerous Crustacea, masses of worms), it 

 is also a striking fact that the fishes live almost exclusively on the 

 soft bottom (or have their main distribution there), since, namely, 

 their principal food is found there. 



Cottus scorpius L. 



This fish has been taken at a definite depth, namely ca. 3 — 15 m 

 (soft bottom of the littoral and Laminaria regions), both in Danmarks 

 Havn and elsewhere in the neighbourhood (at Hvalrosodden off 

 Store Elv). It lives preferably in sheltered places with rich algal 

 vegetation, but it seems to be far from common in these 

 northern latitudes. The depths in which it lives were investi- 

 gated a number of times, and whilst other fishes e. g. Icelus hamatus Kr., 

 Triglops pingelii Reinh. and Gadus saida Lep. occurred in hundreds 

 and Cottus quadricornis L. in tens, only about half a score of Cottus 

 scorpius have been taken (both old and young specimens). Comparing 

 this result w'ith its occurrence on the southern part of the east coast ^, 



1 Ad. S. Jensen: The fishes of East Greenland. Meddel, om Grønland XXIX. 

 Copenhagen 1904, p. 239. 



