KONGL SV. VET. AKADEMIENS HANDLINGAR. BAND 34. N:0 2. .'il 



Thalassiosira gelatinosa Hensen. January: St Vaast r. Februari/: Si Vaasl r; 

 Måseskär r. March: Plym. r; St Vaast r; Ilelder rr; Skagerak w\ April, May: 56 N. 

 7° — 8° K. ?■. November, December: Skagerak, Väderö and Måseskär rr. 



Arctic species, which occurred in A pri 1 1N98 abundantly S. of Iceland, in June 

 L899 at 69° N. 13° W. and in deep-sea collections from 65° N. 1° W. 



T. gravida Cl. — Januari/: Si Vaast rr. Fébruary: St Vaast rr: Väderö and 

 Måseskär er; S. ofNorway +. March: Plym. + r; Skagerak er; Väderö and Måseskär + r. 

 April, May: E. of Scotland to Newcastle r; 56°— 57° N. 0°— 1° E. c; 56 N. 6 E. +; \V. 

 of Deninark r; Plym. + c. October: Plym. c: 



Arctic species, that occurred from March to October 1898 at the Färöes, in 1899 

 March sparingly at 66° N. 20°— 24° W. and more abundant at 65° N. 24° W., in April 

 abundantly at the Färöes and in May at 61° N. 1° W. c. 



T. Nordenskiöldii Cl. — January: Måseskär rr. Fébruary: Väderö and Måseskär er; 

 S. of Norway v. Marek: whole Skagerak cc. April, May: \V. and N. of Scotland c; E. 

 of Scotland, r at some points; 56° N. 6° E. +; N. of Ju tian d r; Väderö and Måscskiir /■/■: 

 Plym. c. November and December: Skagerak and Måseskär rr. 



Arctic species, which occurred in May and June 1898 abundantly X. of Iceland, 

 in May abundantly at the Färöes. In April 1899 it was seen at the Färöes (r c). 



Thalassiothrix Frauenfeldii Gkun. — January: Väderö and Måseskär + c. Fébruary: 

 St Vaast + e; Skagen r; Väderö and Måseskär + c; S. of Norway c. Marek: Skagerak 

 and Måseskär r. April, May: S. of Norway c; Måseskär rr; 56° N. 7° — 8° E. r. June: 

 Skagerak and Måseskär r +. July: Måseskär rr. September to December: Skagerak and 

 Maseskär r. (In December c at Väderö and Måseskär.) 



Northern species, which occurred in November 1898 from S. Iceland to the Shet- 

 lands, as a rule sparingly. 



T. longissinia Cl. & Grun. — January: Väderö c; Måseskär rr. Fébruary: 58° N. 

 2° E. r; S. of Norway r; Måseskär r. Mardi: Väderö and Måseskär r. April, May: 

 58° N. 4° E. r; 57° N. 1° E. c, thence rare towards Skagen; Måseskär rr. 



Arctic species, which in November 1898 occurred as far to the south as between 

 50° N. 10° W. and 47° N. 42° W., in April 1899 at 44° N. 15° W. It has about the same 

 seasonal distribution as Calanus jinmarchicus. 



