26 P. T. CLEVE, THE PLANKTON OF THE NORTH SEA, ENGLISH CHANNEL, ETC. 



E. of Scotland r. September: Hel der r. October: Plym. + ; Måseskär rr; Väderö +. No- 

 vember: 56° N. 4° E. to Skagerak; SW. of Norway rr; Måseskär r; Väderö +. December: 

 Måseskär and Väderö r. 



Tliis species was seen in December 1898 at the Azores and in March 1899 at 

 47° N. 8°W.. 



Chaetoceros diadeina Eiib. — January: Måseskär r. Febr nar//: Helder r; W. of 

 Schleswig r; Måseskär and Väderö c +; S. of Norway r. Mardi: Helder cc; Skagerak ccc. 

 April, May: N. of Scotland r; Måseskär +; 55° N. 7° E. r. June: Måseskär rr. October: 

 Måseskär r. November: Skagerak er. 



Arctic species, which was seen in November 1898 sparingly at 51° N. 20° W., in 

 April 1899 at 48° N. 9° W. and not rare at the Färöes. 



C. didymus Ehb. — Januari/: Plym. r; St Vaast c. Februari/: St Vaast + ; some 

 points E. of Scotland r. March: St Vaast + c. April: Plym. + r; 56° N. 6° E. r. June: 

 Måseskär r. Jul//: Helder r; Gullmarfjord rr. August: Plym. r +; Skagerak r. Sep- 

 tember: Skagerak c; Måseskär cc; Väderö r. October: Skagerak, Väderö and Måseskär + C. 

 November: Irish Sea r; Skagerak cc r; SW. of Norway rr. December: Måseskär +; Väderö r. 



C. f urcellatus Bail. — April: Plym. r. 



This is a characteristic arctic, neritic species. 



C. hiemalis Cl. — Februari/: S. of Norway and at Måseskär r. March: Skagerak + c. 

 April, May: W. of Scotland r, Skagerak ccr; SW. of Norway c; 55° N. G° E. r. June: 

 Skagerak rr; Måseskär +. September: Måseskär + . October to December: Skagerak + c 



C. laciniosus Schutt. — April, May: NW. of Scotland r. November, December: 

 Skagerak, Väderö and Måseskär c r. 



C. Lorenzianus Grun. — August: Plymouth r. 



C. Schuttii Cl. — Februari/: central North Sea r; Skagerak r. March: Plym. r. 

 April: Plym. + r; 56° N. 6° E. r. June: Måseskär re. July: Helder +; Gullmarfjord r; 

 Väderö +. August: Plym. + c; Skagerak and Måseskär cc. September: Skagerak and 

 Måseskär cc; Väderö r. October: Måseskär cc; Väderö r+. November: W. of Denmark r; 

 57° N. 1°E. r; Väderö c. 



C. scolopendra Cl. — January: Måseskär r. Februari/: Väderö, Måseskär and S. of 

 Norway + rr. March: Skagerak er. April, May: Uebrides +; Shetlands r; N. of Scot- 

 land r; central North Sea r; N. of Jutland r; Måseskär r. July: Gullmarfjord. September 

 — November: Skagerak, Väderö, Måseskär and S. of Norway er. 



C. seiracanthus Ghan. — March: Väderö rr. November: Skagerak rr. December: 

 Väderö rr. 



