14 



PLANKTON-TYPES. ARCTIC NERITIC PLANKTON 



jtlanki on-type, Ng. This kind forms a good deal of the S7;y/- 

 plankton of the Skagerak. The mean temperature of the water 

 containing this kind of plankton is, as a rule, low, — 0,5^ to 8,9°, and 

 the salinity is usually considerably below 34 p. m. 



The following list contains the species of this kind of plankton: 



Arctic neritic species. Ng. 



, . ., Mean 



Limits ^ Mean 



T . -.1 tern- ,. ., 



Lat. N. ^ salinity 

 perature 



Clione limacina 82°— 42° 3.3 31.97 



Limacina helicina 81°— 58°(35) 4.2 30.2,5 



Acartia longiremis 80''" — 58° 7.8 33.99 



Pseudocalanus elongatus... 79° — 40° 8.9 34.53 



Amphorella vitrea 80°— 70° — O.3 25.36 



Fungella arctica 80°— 50° 3.5 33.59 



Ptychocylis arctica 75° — 37° 6.0 32.58 



P.^btusa 81°-42° 3.5 33.39 



Tintinnopsis karajacensis... 81° — 69° 2.7 32 45 



Tintinnus bottnicus 81°— 80° 2.7 33.83 



Ceratium hyperboreum 81°— 80° 2.i 29 65 



Peridinium catenatum 80° — 73° 3.2 34.55 



Dinobryum pellucidum 81° — 68° I.9 32.94 



Achnanthes tseniata 80°— 57° — O.3 34.29 



Amphiprora hyperborea ... 80° — 74° — 0.4 32.35 



Chsetoceros bottnicus 80°— 72° —0.4 29.95 



C. diadema 80°— 40°(6) 6.0 33.oi 



C. furcellatus 80°— 59°i50) 4.5 34.03 



C. socialis 74°— 50° 4.5 33.33 



Eucampia gronlandica 78° — 57° — O.2 32. 10 



Fragilaria oceanica 80° — 63° O.s 33.9i 



Lauderia fragilis 80°— 59° O.9 33.3o 



Melosira hyperborea 74° — 75° — O.5 33. 10 



Navicula septentrionalis ... 80° — 69° I.5 32.44 



Nitzschia frigida 80°— 74° —0.4 29.95 



Thalassiosira hyalina 80°— 63° 1.8 34.59 



T. Nordenskioldii 80°— 40° 7.4 34.53 



Outside 

 the Atlantic 



Circumpolar. 

 C^ircumpolar. 



New Siberian Islands. B. 

 New Siberian Islands. B. 



B. 



B. 

 B. 

 B. 



North P. 



