32 v. T. CLEVE. THE PLANKTON OF THE NORTH SEA AND THE SKAGERAK:. 



and Sk. common in some spöts; 55° N. 6° E.; Sk. and M. very common. Mm/: M. c. 

 Juve: the Shetlands -|— Octoher: V. r. November: Sk. rr, Vinga r, V. and M. -|-. De- 

 cember: M. and V. r -j-. 



R. setigera Brtw. — January: Vinga, M. and V. r. February: M. c. March: 

 56°55'N. 12° 16'E., Middelgrundet, Vinga, M. +. Äiyril: Sk. not rare, M. r. SejJtem- 

 ber: M. r. October: V. r. November: off the Dutch coast and N. of Jutland r, Vinga 

 (30 m.) r, M. r, V. r +. December: M. and V. r. 



R. Shrubsolei Gl. — June: the Shetlands r. July — Aiujiist: W. of Jutland -j-, M. -|-, 

 V. r. October: M. r, V. -|-. November: Sk. r. December: V. rr. 



R. Stolterfothii H. Per. — April: off the Dutch coast +; at 57° N. 4° E. r. July 

 — August: W. of Jutland -|-. September: M. r. October: M. and V. r. November: off 

 the Dutch coast; N. of Jutland, V. -f-. 



R. styliformis Brtw. — February: r at 58° N. 3° E. April: E. of Scotlaiid and 

 W. of Schleswig rr. May: N.E. of Scotland c. June: the Shetlands c. July — August: 

 common along the Dutch coast, thence more sparingly to Limfjord, the Shetlands -|-, M. 

 c. October: V. r. November: W. of Scotland r, more or less common from Holland to 

 Sk., Vinga (30 m.) +, M. r. 



Ropevia tessellata Roper. — November: N. of Scotland, N. of the Dogger Bank and 



at Sk. rr. 



Skeletonema costatum Gren. — February: M. c. April: 57° N. 9° E. r, Sk. r, M. r. 

 September: M. cc. October: M. cc, V. -)-. November: N. of Jutland rr, Vinga (30 m.) r, 

 M. and V. r. December: M. and V. ■;■. 



Stephanopyxis turris Grev. {St. furgida Grev.). — January: central Skagerak rr. 



October: M. and V. rr. November: N. of Jutland r, S. of Norway r, Vinga (30 m.) -f-, 

 M. rr, V. r. 



Thalassiosira gelatinosa Hensen. — January: central Skagerak r. March: Vingn r. 

 November: W. of Scotla.nd, N. of Holknd and N. of Jutland, everywhere r. December: V. r. 



T. gravida Cl. — March: M. r. April: area between 56°— 57° N. 2°— 5° E. No- 

 vember: N. of Jutland rr. December: V. r. 



T. Noi"denskiöldii Cl. — January: central Skagei-ak rr, Vinga rr, V. rr. February: 

 M. c. March: from 56° 33' N. 12° 16' E. to M. very common. April: area between 56° 

 — 57°N. 2°— 5°E. and 55° N. 6°— 7° E.; Sk. c, M.' r. .Tune: the Shetlands +. Decem- 

 ber: V. r. . ■ .; : ; ^^ \i . ; .; i ■ i- .. 



Thalassiothrix Frauenfeldii Grun. — January: central Skagerak and Vinga c, M. 



and V. r. February: M. c. April: 57° N. 5° E. r,'Sk. +, M. +. October: M."c. No- 

 vember: N. of Jutland r, Vinga (30 m.) -)-, M. and V. -\-. December: M. and V. c. 



T. longissima Cl. & Grun. — July: the Shetlands r. 



