88 DISCOVERY REPORTS 



PART III. THE ZOOPLANKTON 



SECTION I 



By E. R. Gunther, m.a. and A. C. Hardy, m.a. 



INTRODUCTION 



The methods of collection have already been described on pp. 17-19- The 70 cm. 

 diameter nets, hauled both vertically (N 70 V) and horizontally (N 70 H), were used for 

 the capture of the smaller and medium-sized forms, and the 100 cm. diameter nets 

 (N 100 H), towed horizontally, were used for the larger forms. The distribution of the 

 Tintinnidae, which are too small to be taken in representative numbers by the N 70 V 

 nets, has been obtained from the N 50 V samples. 



As with the phytoplankton, no attempt has been made in the present work to identify 

 specifically all the forms met with; the object has been to gain a knowledge of only the 

 more important elements of the plankton community. It aims at laying the foundations 

 for a study of the ecology of the plankton which may be added to by future surveys. 

 The identifications in some groups have been carried farther than in others when we 

 have had the assistance of experts in these particular groups ; thus the late Mr Andrew 

 Scott has identified nearly all the species of Copepoda. All the material is kept and it is 

 hoped that in time systematic reports on all the groups will appear. 



Our previous knowledge of the zooplankton of the Antarctic is based on the collections 

 made by a number of expeditions from the voyage of the ' Challenger' onwards. These 

 expeditions were not concerned with studying the ecology of the plankton, and the 

 reports on the collections are mainly systematic in character. The more important 

 former records of the different species are referred to in the text, and for the sake of 

 brevity, when making such references, the full name of the expedition will not be given, 

 but usually only the name of the ship, together with the name of the author of the 

 particular report concerned. The following list, arranged in chronological order, gives 

 the fuller titles and dates of the expeditions referred to : 



' Challenger.' Voyage of H.M.S. ' Challenger', 1872-6. 



'Belgica.' Expedition Antarctique Beige, 1897-9. 



'Valdivia.' Deutschen Tiefsee-Expedition, 1898-9. 



'Southern Cross.' British Antarctic Expedition, 1898-1900. 



'Discovery.' National Antarctic ('Discovery') Expedition, 1901-4. 



'Antarctic' Swedish Antarctic Expedition, 1901-3. 



'Gauss.' Deutschen Siidpolar-Expedition, 1901-3. 



'Scotia.' Scottish National Antarctic Expedition, 1902-4. 



'Francaise.' Expedition Antarctique Francaise, 1903-5. 



'Nimrod.' British Antarctic Expedition, 1907-9. 



'Pourquoi-Pas?.' Deuxieme Expedition Antarctique Francaise, 1908-10. 



'Terra Nova.' British Antarctic ('Terra Nova') Expedition, 1910-13. 



'Aurora.' Australian Antarctic Expedition, 1911-14. 



'Endurance.' Shackleton's Expedition of 1914-17. 



'Norvegia.' Norwegian Antarctic Expedition, 1927-9. 



'Vikingen.' Norwegian Antarctic Whaling Expedition, 1929-30. 



