208 



POPULATIONS OF THE SEA 



Centropages lypicus -c 

 Anomalocera palerson 



Calanus hyperboreus-C 

 Melndia Jonga-C 

 Ceralium arclicum-P 

 Pareuchaeta norvegica -c 

 Ihtea asymmetrica-y 



Salpa fusiformis-J 



Cerotium lineatum-p 

 Dactyliosolen medilerraneus-P 

 Thalassiothrix longissima-P 

 Rhizosotenia alata indica -P Metndia lucens c 

 Aetidius armatus C 

 Pleuromamma robusta-C 

 Euclio spp -M 

 Dolioletta gegenbauri-T 

 Ceratium hexacanthum-P 

 Rhincalanus nasutuS-C 

 Pleuromamma abdominal is C 

 Pleuromiamimia gracilis - c 

 Pleuromamma borealts-c 

 Pleuromamma xiphias-C 

 Ceralium azoricum-P 

 Calanus minor-C 

 Euchaeta acuta ~c 

 Calanus gracilis-c 

 Thalia democratica-T 

 Atlanta spp-M 

 Diacria Inspinosa-M 

 Sapphinna spp. -C 

 lasis zonaria-"! 

 Centropages bradyi -C 

 Doliolum nationalis-T 

 Ceratium carnense- P 

 Doliolina mulleri -T 



Ceratium Iusus-p 

 Ceratium lurca-P 

 Ceratium tripoSP 

 Ceratium horridum-p 

 Rhizosolenia Styliformis-P 

 Rhizosolenia hebetata semispina-p 

 Tnalassionema nitzschioides-P 

 Acartia spp-c 

 Corycaeus spp-c 



Calanus fmmarchicus-c 

 Limacina retroversa->-\ 



Clione limacina t^ Rhizosolenia alata alata p" 

 Candacia ormofo cfv^ Para-Pseudocalanus 

 Euchaeta ^»ebes-c] ^^^ Ceratium macroceros-P 



Ceratium longipes p 



INTERMEDIATE 



Temora longicorms C 

 Centropages hamatus-C 

 Asterionella japonica-P 

 Biddulphia aurita P 

 Biddulphia sinensis p 

 Labidocera wollastoni -c 

 Isias clavipes-c 

 Ouinardia tlaccida -P 

 Phaeocystis spp p 

 Bellerochea malleus-P 



NERITIC 



OCEANIC 



Fig. 2. A biogeographic series for the nortlieastern Atlantic and tlie Xorth 

 Sea, derived from the Continuous Plankton Recorder Survey. The organisms are 

 arranged so that the distribution of each species is similar to that of its neighbors 

 in the series. P, phytoplankton; C, copepods; M. molluscs; T, tunicates (Cole- 

 brook et al, \96\). 



tive without any implication of the mechanisms which may de- 

 termine or limit distribution. 



A small fourth group does not fall easily into the series and is 

 unclassified ; it contained four species of dinoflagellates, two dia- 

 toms and two copepods. All of them were widely distributed and 

 they showed many of the expected features, such as the gradients 

 of abundance parallel with the continental shelf. It is possible 

 that they were ubiquitous within the area of the survey, but pre- 



