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



Seasonal distribution of the Plankton-organisms. 



Appendicnlaria. 



Fritillaria borealis Lohm. — Februari/: off S. Norway and W. of Jutland r. Marek: 

 Plym.*) r; Väderö c. April: 55° N. 6° E. r; Måseskär ?•. It reappeared at Plym. in Oc- 

 tober and November. 



This arctic species was found in March to May from the Färöes to 61° N. 1° E. 

 and 59° N. 2° E. 



Oikopleura dioica Fol. — Februari/: W. of Jutland r. May: 60° N. LE. and 58° N. 



4° E. c; 58° X. 9° E. r. July, August: Helder r\ E. of Xewcastle r; central North Sea r; 

 the W. coast of Denmark to Skagen and into the Skagerack r to c. It remained in the 

 Skagerak to the end of the year, but decreased in frequency in November and December. 



Pteropoda. 



Clione limacina Phipps. Arctic species. 

 Januari/: Väderö rr. 



Limacina balea Möller. Arctic species, which was seen in December 1898 from 

 64° N. 21° W. to 61° N. 6° W. 



Januari/: Väderö rr; Måseskär cc. Juli/: 57° X. l u E. +. August: Skagerak r. 

 September: Skagerak r. October: Väderö +. November: 56° 24 — 57° 10' N. 4° 25'— 7° 40' E. c; 

 Skagerak r. 



• 



Amphipoda. 



Bathyporeia pelagica Bate. — Februari/: W. of Denmark rr. 



Parathemisto oblivia Kröyek. — January: Måseskär rr. July: 57° N. 1° — 2° E. r. 

 This species occurred in October 1898 at the Färöes. 



Proto pedata Leach. — Januari/, Februari/: W. of Denmark r; Måseskär r; VäderÖ + . 

 November: from the Engl. Channel to the W. of Jutland r; Skagerak r. December: Mäse- 

 skär r; Väderö +. 



*) Abbreviation for Plymouth. 



