X\\ <'■ II- ()sii:m 1,1.1) and ()\i; I'ai i.skn. 



Injpciborca, sin;ill (|iianlily ol' Cosciiwdisciis siibbnlieiis, Chact. boréale 

 and 67i. \Vi(/h(uni. 



The inteiinediate group (ö sanij)les) extends Irom ca. l'i lo 8° 

 W. L.; here we have a salinity ol" ca. lU"/"*' i>»d a surface Icuiper- 

 aturc of — 6'^ lo — 15° C. It is chaiacleiized by the following species, 

 which arc hardly al all found inside: Cliaetoceras fnrcellaliim, Rhi- 

 zosnh'iiid obliisd, Rh. hcbetala f. seniispina, Dinobrijon pcUncUlum, (lijtld- 

 rocylis (lenticiiUita tijpica. A few species, which very seldom occur 

 in Ihe inner group, appear here more regularly, namely, Chaet. diu- 

 dema, Peridinium paUidnm, P. pellncidnm and P. ovatiim. Thalassi- 

 osira gravida, which was much reduced, again becomes more fre- 

 quent in this region. Mosl of the species prominent in Ihe inner 

 group disappear here or are only present in small quantity. 



A couple of samples form the transition lo the outer group, to 

 which we ascribe the region from ca. 7" to iy^ W. L. and from 75^ 

 to 73°N. L. The salinity is here higher (33— 34<^/oo) and also the 

 temperature on the surface (6° — 7°) than in the other regions; we 

 are here outside the pack-ice. The quantity of the plankton is but 

 small; the diatoms have almost entirely disappeared; characteristic 

 however is the regular occurrence of Cliaetoceras convoluimn in small 

 ([uantities; further, a number of diatoms of more temperate origin 

 appear irregularly and in few individuals and likewise some Pro- 

 tozoa (see our preceding papers). The most abundant organisms are: 

 Peridinium ovatiini, Dinobrijon pellucid uni, Cyttarocylis denticulata ty- 

 pica and robusta, Oithona and Nauplii, and in most samples Cera- 

 tiiim arcticuni, Tinfinnii.s norueyiciis gracilis and Peridinium pyriforme. 

 In a few samples occuried Phaeocystis Pouchetii, Pontosphaera bore- 

 alis and Coccolithophora pelagica. 



The plankton in the outermost samples corresponds nearest lo 

 the "Ceratium arcticum plankton", which Paulsen (19Ü9) has 

 described from North Iceland (the southern boundary of which is pla- 

 ced at ca. 64 N. L. in his fig. 2), but differs from this in the absence 

 of Ceratium longipes (the C. arcticum most resembling longipes is 

 figured in the foregoing paper fig. 16 A). 



A general review of the plankton of the pack-ice and 

 coastal waters, according lo the samples examined, would appear 

 somewhat as follows. In the accompanying sketch map the plankton 

 regions and the places of the samples (the figures refer lo the Tables) 

 have been marked out. There are three regions. 



1. Innermost the plankton region of the coastal waters 

 (inner group in 1906 and 1908), characterized by diatoms, namely 

 Chaetoceras species, Coscinodiscus subbuliens, Fragilaria oceanica and 

 by Calanus finmarcliicus. 



