ON ANIMAL COMMUNITIES IN THE SOUTHERN NORTH SEA. 27 



3. Animal Oonmiuuitie.s in the Southei'n Nortli Sea. 

 By H. Blegvad, Dr.Phil., Assistant at tlie Danish 

 Biological Station *. 



[Received December 24, 1921 : Road February 21,;1922.] 



(Text-figure 1.) 



Haviug determined the quantity and charted the distiibution 

 of the bottom animals in the Danish Seas (" Valuation of the 

 Sea," I, and 11. : Reports XX. and XXL, from the Danish 

 Biological Station, 1911 and 1913), Dr. 0. G. Joh. Petersen in 

 1914 published an appendix to Report XXL (in Reports from 

 the Danish Biological Station, XXIL, 1914), in which he, on the 

 basis of various statements in the litei*ature, gave a hypothetical 

 chart of the animal communities outside Denmark. In this 

 the North Sea is charted as chiefly a " Vemis ''-community, with 

 the '^ Macoma bcdtica" commvxnity in some places along the 

 shore, and an area in the deeper parts of the North Sea, marked 

 with a ?, in which several indications in the literature suggested 

 the occurrence of a " Brissopsis "-community. In the month 

 of July 1921 1 was enabled to accompany the English Fishery 

 Research vessel ' George Bligh ' on a cruise across the North Sea 

 from Lowestoft to Esbjerg, during which Dr. Petersen's bottom 

 sampler, " the Petersen Grab," was used ; by the courtesy of the 

 Director of Fishery Investigations, Dr. E. S. Russell,! was given 

 permission to work out and publish the material procured. 

 Though the route followed did not touch the deeper parts of the 

 North Sea, as will be seen from the accompanying chart of the 

 stations (p. 30), and consequently cannot give information about 

 the existence or not of the ''Brissopsis " area mentioned above, still 

 the 20 stations worked during this cruise can be of service in 

 giving a preliminary orientation of the communities in the 

 Southern North Sea. 



In the accompanying Valuation List the stations have been 

 arranged in communities. It will be seen that with some 

 hesitation I have referred the first two stations to the " Veuus"- 

 community. These two stations contain, however, too few 

 bottom animals to settle the question. Among the characteristic 

 species of the " Macoma bcdtica" community, which, with the 

 kind help of Captain Davis, I found in large quantities by digging 

 along the shore-line at ebb-tide in the harbour of Lowestoft, viz., 

 Macoma bcdtica, Scrobicularia plana, Mya arenaria, and Carclium 

 eclule, only one small Mya arenaria was found, at Station 2 ; 

 whereas a representative of tlie " Epi-Fauna " of this community, 

 viz. Mytilus eclulis, is present in numbers at this station. On the 

 other hand, a small Ofhioglypha cOMcla and two Natica cdderi point 



* Comrauuicated by E. S. Russell, M.A., D.Sc, F.Z.S. 



