354 DEPTHS OF THE OCEAN 



material from representative stations, and upon observations 

 of the living organisms on board ship. 

 The coast All our first stations about the middle of April, with the 



No'nh Europe, ^xception of Stations i and 5, that were close in to land 

 (Stations i-io, and had a less abundant flora, had an extremely plentiful 

 Aprfu^ diatom-plankton, such as we only get in the waters of North 



Europe during the spring. Our experiments with the closing- 

 net, which, thanks to the fine calm weather, were made with 

 the utmost exactitude at Stations 3 and 10, showed that by far 

 the larger number were to be found between the surface and 

 a depth of 100 metres, though even at a depth of 100 to 150 

 metres there were still quite considerable quantities. The 

 character of the flora was mainly northern, especially in the case 

 of the oceanic species. Among the principal forms we got 

 Rhizosolenia hebetata forma se7nispina and Nitzschia seriata. 

 Neritic diatoms were also numerous, and some had resting- 

 spores. They are of a distinctly southern character compared 

 with the species which occur, for instance, along the coasts of the 

 North Sea ; further, they belong to a local flora, which does not 

 seem to have any direct connection with the North Sea. On 

 the whole, these neritic diatoms are so small in their dimensions 

 that they show signs of an "oceanic degeneration." 



Besides them, there was an addition of subtropical species, 

 especially in the deeper layers, and especially at the southern- 

 most stations, Nos. 9 and 10, consisting of both diatoms and 

 peridinese, not in any great quantity, but still occurring regu- 

 larly. These are the northernmost outposts of the Desmo- 

 plankton, including such species as Planktoniella sol, Ceratmm 

 gibberuni, Dinophysis schuttii, and D. uracantha} 



The coast Throughout the stretch of sea along the coasts of South 



Europe anT Europe and North Africa our investigations were carried 

 North Africa, on Comparatively close to the coast, and the plankton was 

 4i,Vi°srAprii- generally found to be poor both in quality and quantity as soon 

 22nd May.) as we stood at all far out from the land. It was then 'composed 



^ As representing this area, I here give a list of species from Station 7, depth 0-20 metres : — 



Oceanic diatoms : ChcBtoceras decipietis, C. densum, C. convolutum, C. periivianum, 

 C. atlatiticum, C. dichceta, Coscinodisctts centralis, C. margutatus, Euodia cuneiforniis, Thalassio- 

 stra subtilis, Asteromphalus heptactis, Rhizosolenia alata. A', seinispitia, E. stolterfotkii, 

 R. shrubsolei, R. acuminata, R. amputata, Dactyliosolen antarcticus, Nitzschia seriata, 

 Thalassiothrix longissinia. 



Neritic diatoms : Chcetoceras diadema, C. schiittii, C. contortum, C. coronatum, C. scolo- 

 pendra, Bacteriastrum varians, Eucampia zodiactis, Thalassiothrix nitzschioides, Cerataulina 

 bergonii, Dattyliosolen tenuis, Thalassiosira decipiens, T. excentrica, T. tiordenskioldii. 



Peridineae : Ceratium tripos forma atlantica, C. lamellicorne forma compressa, C. azoricum, 

 C. furca, C. arietinum, and several others. 



Coccolithophoridffi : Distephanus speculum, Coccolithopkora pelagica. 



