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ON THE MARLNE F^AUNA OF THE ISLES OP SCILLY. 

 By EDWARD T. BROWNE aud RUPERT VALLENTIN. 



Part I. 

 THE PELAGIC FAUNA. 



By EDWARD T. BROWNE. 



Introductioti. 



The Isles of Scilly occupy an excellent geographical position 

 for the study of Marine Biology, as they are about thirty -five 

 miles westward of the southern extremity of Cornwall. 



Our knowledge of their Marine Fauna is not very extensive, 

 and it is strange that they have been so seldom visited by marine 

 naturalists, as they are so accessible from Penzance. 



Their exposed and isolated position gives a distinct advantage 

 to plankton investigations over dredging and shore work. They 

 are in the midst of a good tidal stream, and are most favourably 

 situated for currents, especially those produced by westerly or 

 south-westerly winds. As the prevalent wind is south-westerly, 

 it produces not only a very mild climate in winter, but, at times, 

 a current known as Eennell's Current, which brings inshore the 

 pelagic inhabitants of the Atlantic Ocean. It is these "visitors" 

 to our shores, or the expectation of them, that gives a fascination 

 to plankton work and prevents it from ever becoming monotonous. 



The records of the pelagic fauna in this report are based 

 upon two visits to the islands, and as they were far apart it will 

 be best to keep their records separate. 



The First Visit, 21st to 26th July, 1899. 



Mr. J. W. Woodall kindly invited Dr. E. J. Allen, Mr. W. 

 I. Beaumont and myself for a scientific cruise among the islands 

 in his steam yacht " Vallota." The yacht was a great advantage, 

 as we were able to explore the numerous channels between the 

 islands and to find quickly the places most suitable for tow- 

 netting and shore-work. The investigation of the plankton, 

 perhaps unfortunately, fell to my share and consequently the 

 Medusae received more direct attention than the other groups. 



