108 



E. Joigen 



P. tenitissimum ^^'. Sm. vav. byperborea Grin. 

 (PI. VII, fig. 19). 



Geun. L. 48, p. 58, pi. 4., f. 77. 



Answers well to Grunow's illustration and description, but is 

 also very like P. Spenceri W. Sm. var. borealis Geun. 1. c. p. 60, 

 pi. 4, f.'79. 



Very scarce and i-are: Lille MoUa, 'A 1899, near the surface; 

 POlstad 74 1899, 0—3 ni. 



Distrihutimi : The Kara iSea. 



P. fasciola (Eurb.) W. Sm. ami P. teniiirostre Ghun. 



Both these species, the latter of which is considered to be a 

 Ibini of the former both by Cleve and others, occur occasionally 

 during the spring diatom inflow, but alway.s very sparsely. It is 

 doubtful if these species really are plankton forms. P. tenitirostre 

 seems to be the more frequent. 



Strange to say, 1 once saw oblique striæ very close to each 

 other (but only in one direction), closei- than the transverse striæ, 

 about 27 on 10 ix. The transverse striæ were only discernible near 

 the raphe, about 20 on 10 \i-. Longitudinal lines were only to be 

 seen at the ends, somewhat wslvj (PI. VII, f. 20). 



Generally speaking, striæ were not seen in the specimens 

 (which were thin walled), so that I cannot decide whether the 

 difference mentioned bet\\een I\ fasciola and P. tcnuirostris holds 

 good with us or not. At any I'ate, the shape of the latter species 

 is very characteristic. 



Distribution : P. fasciola is widely distributed on the European 

 coasts. P. teniiirostris is an arctic form, known from Greenland 

 and the Kara Sea. 



P. uaviciilacemu ISrkd. 

 Not a genuine plankton form. Refer to bottom samples. 



Rlioicosignia arcticum Cl. 



Rare and scai'ce. Hardly a genuine plankton form. Seems to 

 be a fre(|ucnt bottom foi'ni on the west coast of Norway, and pro- 

 bably also iin tiie north coast. Refer to bottom samples. 



Auricula complexa (Gueg.) De T. 



Only once found, singly: Rombaken "/■• 1899, — 40 m. 

 Distribution: Tlic coasts of Great Britain. Rare on tlie west 

 coast of Norwav. Also mentioned from Barbadocs. 



11. IE>e3r±ca-±i3_±ales. 



I. Proroccntraceae Sikin. 

 Proroceiitriiiii micnns Kiiun. 



Only once found, very scarce: Henningsvær, '"A 1899, 0— 

 180 m. On account of its small size it goes through the net. 



Distribution: Probably a coast form from the temperate 

 European coasts of the Atlantic and its arms. Known from the 



North Sea, (from the English Channel, not rare. May 1903 L. 18, 

 IV), Skagerack, the Baltic and the west coast of Norway, here 

 rather scarce. Probablv brought to us from southern coasts. 



IkiiiopliyMis Ehrb. 



D. acuta Ehrb., .Jorg. 



.TuKG. L. 91. p. 28, pi. I, f. 2. 



Rather common in the samples, but always rather scarce. 



Distribution: Seems to be a northern, but not an arctic, form, 

 which is frequent both in the open sea and on the coasts. Kno\\n 

 from the watei-s between Norway, Scotland, Iceland and Greenland 

 as well as from the North Sea, Skagerack and the Baltic. It 

 appears to be stationary on the west coast of Norway and near the 

 Faeroe Islands and Iceland, probably also on the northern coasts 

 of Norway, where it has been found at several places by Gkan 

 in the summer and autumn months. (Cfr. Gran L. 67). 



D. uorregica Clap, et Lachm., .Jorg. 



JuRG. L. 91, p. 29, pi. 1, f. 3—6. 



Occurs in many of the samples, but always in small lunnbers. 



Distribution: Not sufficiently known. The species, however, 

 appears mostly to have the same distribution as D. acuta. Seems 

 to be a northern form. Known fi'om the North Sea (from The 

 English Channel, r May 1903), Skagei'ack and Cattegat, Scotland, 

 Jan Mayen and the west coast of Norway, where it is found, but 

 only sparsely, during nearly all the months of the year. 



D. acuminata Clap, et Lachm., .Jorg. 



J(')EG. L. 91, p. 30, pi. I. f. 7—9. D. Vauhoffhii Ostenf. 



Very rare and scarce. 



Distribution: Not sufficiently known. Seems to be a northern 

 form, but scarcely native with us. Rather frequent on the west 

 coast of Norway in the summer and autumn (of 1898), but gener- 

 ally scarce. Also known from Greenland, Iceland, the Faeroe Is- 

 lands (very rare) and the Baltic Sea (Levandee). 



Perhaps it comes to our west coast from Iceland. 



D. rotuitdata I'lap. et Lachm. 



D. Michaelis auct p. p. 



Rare and scarce. Found in small numbers by Gran (L. 67) 

 at several places on the nortiiern coast of Norway in the mont lis 

 of July— Octobex 1898—99. 



Distribution: Seems to be a northern, oceanic form. KnoA\n 

 from the North Sea (southwards to the English Channel, r in I'c- 

 bruary and May 1908), Skagerack and also mentioned from tiie 

 Baltic. On the west coast of Norway in the months of April — De- 

 cember 1898, always in small numbers. 



D. bomunculus Stein. 



Stein L. 13.'), pi. 21. f. 1—8. 



Only found in one of the sanii)ics (two indi\'iduals). Helligvær 

 1-/, 1899, 0—50 m. 



Distribution : Widely disti-ibuted in the warmer parts of tiie 



