304 Ove Paulsen. 



The following papers deal with the Peridiniales of the East- 

 Greenland sea : 



Cleve, p. T. : Report on the Plankton collected Ьл' the Swedish expedition to Spitz- 

 bergen in 1898. (K. Svenska Vet. Akad. Handl. ;i2, 1899). 



Paulsen, Ove: Plankton investigations in the Avaters round Iceland in 1903 (Meddel, 

 fra Kommis, for Havundersøg. Ser. Plankton. Bd. I. No. 1. 1904). {Cited as: 

 Plankton invest Iceland 1903). 



Broch, Hj.: Plankton tables. In Damas et Koefoed: Le plankton de la mer du Grön- 

 land. (Duc d'Orléans: Croisière océanographique accomplie A bord de la Belgica 

 dans la mer du Grönland 1905). Bruxelles 1909. 



Paulsen, Ove: Plankton investigations in the waters round Iceland and in the North 

 Atlantic in 1904. (Meddel, fra Kommis, for Havundersøg. Ser. Pankton. Bd. I. 

 No. 8). 1909. 



Broch, Hjalmar: Das Plankton (Zoologische Ergebnisse der Schwedischen Expedition 

 nach Spitzbergen 1908. Teil I, 2). (K. Svenska Vet. Akad. Handl. 4Г), No. 9. 1910)'. 

 (Cited as: Broch, Spitzbergen Plankton . 



Yet, for easy reference, b}' each species the following paper is cited: 

 Paulsen, Ove: Peridiniales (Nordisches Plankton, herausgeg. v. Brandt u. Apstein 

 XVIII). Kiel 1908. 



Dinophysis Ehrenberg. 



1. Dinophysis norvegica Claparède & Lachmann, Mém. inst, 

 nat. Genév. 1859, p. 407, tab. XX, fig. 19. Paulsen Nord. Plankton, 

 p. 14, fig. 11 — 12. Broch Spitzbergen plankton 1910, p. 31, lig. 1, I. 

 D. acuta auct. plur., non Clap. Lachm. 



Single specimens, agreeing with var. crassior, Paulsen 1. с and 

 also with Brochs drawing, were found in the outer part of the pack- 

 ice and in the open sea. 



Distrib. Seems to be a neritie and l)oreal but hardly arctic species. 



2. Dinophysis arctica Mereschkowsky, Archiv f. mikroskop. 

 Anatomie 1879, p. 177, tab. XI, fig. 19. Paulsen Nord. Plankton 

 p. 15, fig. 14 (a bad figure), Broch Spitzbergen plankton p. 81, fig. 1, 

 II. D. granulata Cleve & auct. plur. 



Broch (1. с.) says that this species bears fine and distant poroids 

 on the surface while D. norvegica is coarsely areolated. My annexed 

 fig. 1 shows that this is not always the case, this specimen (and 

 many others) being very coarsely areolated. Besides, 1 have often 

 found cells of this species provided with small protuberances at the 



^ In this paper which appeared as I had finished the examination of the plankton 

 samples, Bütschli's theory on the intercalary striae as growth-marks is shown to 

 hold good, the growth of the différent species is studied in detail, and the 

 arrangement of their plates is expressed in formulae. It will realh^ be an ad- 

 vantage if the plate-arrangement proves to be so constant as supposed Ьл' Broch. 

 — A lack in Broch's paper is that he gives no measures of the organisms, he 

 confines himself to criticise those given by me. His paper will be often men- 

 tioned in the folloлving. 



