KONGL. SV. VET. AKADEMIENS HANDLINGAK. BAND 35. N:0 7. 



15 



Peridinium divergens + , 

 Pyropliacus horologium r, 

 Chcetoceros Schuttii r, 

 Roperia tessellata rr. 



The in^os- plankton contained thus, as usually, a mixture of southern and noi^thern 

 forms, the former far raoi-e prevalent in number of individuals. This kind of plankton 

 evidently originates N. of Scotland by the fusion of water from the temperate eastern 

 Atlantic with water from Iceland, the Färöes and the Shetlands. 



As characteristic for the 34 p. m. water or occurring there more frequently than 

 in the 33 p. m. water, I consider the foUowing forms: 



Forms of southern origin. 

 Acartia Clausii r, 

 Lahidocera WoUastotiii rr, 

 Evadne spinifera r, 

 Podon intermedius rr, 

 Acanthochiasma fusiforme r, 

 Acanthonia Mälleri r, 

 Halospliwra viridis + , 

 Ceratium buoephalum c, 

 Peridinium Michaelis rr. 



Forms of northern origin. 

 Spirialis retroversa r, 

 Acartia longireniis r. 

 Centropages hamatus rr, 

 yiSternhaarstatobla.sfy Hensen 

 Ceratium longipes + , 

 Peridinium depressuin + , 

 Pterosphwra Möhii rr, 

 Kanthidiutn multispinosuni r. 



Water of 33 — 28 p. ra. salinity contained, besides such forms as occurred as fre- 

 quently in the 34 p. m. water, the following species: 



Forms of southern origin. 

 Oikopleura dioica r, 

 Corycceus anglicus + , 

 Euterpe acutifrons r, 

 (^Amphorella suhulata rr), 

 Codonella Jörgenseni rr, 

 Cyttarocylis serrata r, 

 {Tintinnopsis beroidea + ), 

 T. campanula + , 

 Noctiluca miliaris r, 

 Ceratium lineatuni rr, 

 Diplopsalis lenticula + , 

 Peridinium peduricidatum r, 

 Prorocentrum, micans r, 

 Bacteriastrum, varians r, 

 Bellerocliea mallens rr. 

 Biddnlphia mobilensis c, 

 Cerataulina Bergonii r, 

 (Clicctoceros contortus c), 

 C. curviseius c, 

 C. densus + , 

 C. didymus c, 

 Ditylurn Briglilwellii c, 



Forms of northern origin. 

 Fritillaria borealis rr, 

 Plectophora arachnoides rr, 

 Binophysis Vanhöffenii rr, 

 Peridinium ovatum r, 

 (JCantliidium brachiolatum r), 

 Phaiocystis Pouahetii rr, 

 Chwtoceros borealis r, 



var. Briglitwellii rr, 

 C. constrieius rr, 

 C. debilis c. 

 C. diadem a r, 

 C. laciniosus r, 

 Cpscinodiscus concinnus + , 

 (C. excentricus + ), 

 Rhizosolenia setigera r, 

 Skeletonema costatum, rr, 

 Thalassiosira gelatinosa r, • ; 

 T. gravida rr. 

 Thalassiothrix Frauenfeldii r. 



