14 P. T. CLEVE. PLANKTON, COLLECTED BY THE SWEDISH EXPEDITION TO SPITZBERGEN. 



Deep-sea Plankton. 



At sorae stations plankton was gathered by hauls from different depths. As Dr. 

 AuRiviLLius will describe the animals found in these sainples, I have examined the vegetable 

 plankton and the radiolarians only, and being thus unable to give a complete account of 

 these gatherings I confine myself here to shortly characterizing them so far as regards the 

 phytoplankton and the radiolarians. 



1. Station M. 26 to 27 July. Lat. 77° 39'. Long. 1°18'E. 100— O metres. 

 Salinity at 100 m. 34,97, in the surface 32,22. Temp. 5,07. 



This sainple contained trichoplankton {Chcetoceros criophilus, Rhizosolenia obtusa) 

 and some arctic neritic plankton {Dinobrynm), but the animals indicate the presence of 

 an araount of styliplankton of the same kind as in the surface west and south of Spitz- 

 bergen in August and September. 



2. Station N. 28 July. Lat. 77° 52' N. Long. 3° 5' W. 



a. Haul 10 — O m. Temp. at O m. 3,6;^. Salinity 34,38. Chiefly chaatoplankton 

 (Chcetoceros decipiens, Phceocystis Pouchetii) and arctic neritic plankton {Dinobryum). 



b. Haul 25 — O m. Temp. at 25 m. 2,72. Salinity 34,74. The same kind of 

 plankton. 



c. Haul 100 — O m. Sal. at 100 m. 35, os. Plankton sparingly {Pha^ocystis Pouchetii). 

 cl. Haul 500 — O in. Temp. at 100 m. -[-0,83. Sal. 35,03. Content the same as a, 



but, in addition, Rhizosolenia gracillima and some animals of the styliplankton-type. 



The conclusion is, that the deeper strata contained styliplankton, the upper chasto- 

 plankton. 



3. Station O. 29 to 30 July. Lat. 78° 13' N. Long. 2° 58' W. 



a. Haul 100 — O m. Temp. at O m. 3,i, sal. 33,76; at 100 m. I,i7, sal. 35,03. 

 Content: chiefly Phceocystis Pouchetii, thus chastoplankton. 



b. Haul 500 — O vi. Temp. at 500 m. 0,95, sal. 35,03. Content as a, and besides, 

 rarely Challengeria tridens and some other styliplankton forms. 



c. Haul 2,600 — O m. Temp. at 2,700 m. — 1,48, sal. 34,96. Chiefly as a but 

 with radiolarians of many species sparingly. Among the radiolarians were found a number 

 of new forms which will be described further on. Among known forras Aulacantlia 

 Icevissima, Challengeria tridens and Trochodiscus echinidiscus are known from the Färöe 

 Channel, Stichopilium Davisianum from the bottom mud near Greenland, also Artro- 

 strobus annulatus, which latter was first found near Kamtchatka. Diciyophimus gracilipes 

 is known from Kamtchatka only. Challengeria Harstoni was dredged by the Challenger- 

 expedition from the abysmal depths east of Japan. Among the new forms is Polypetta 

 holostoma, allied to P. tabulata from the central Indian Ocean. Åulodendron antarcticum, 

 Auloscena sjjectabilis and Sagenoscena penicillata are known from the Antarctic Ocean only. 



