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



Proto pedata Leach. — Januari/ and February (31. I and 1. II): rare in the Skagerak. 

 August: from the E. Channel to Helder. November: north of Holland and west of the 

 Danish Peninsula, west coast of Sweden, where it was abundant in December. 



Cladocera. 



Evadne Nordmaiinii Loven. — May: at Måseskär. June: common in the North Sea, 

 between 56° and 58° N., from W. Norway to 0° 38' E. and to Skageii, common in the 

 Skagerak, where it remains until August. Along the coast it remains in October. Rare at 

 Plymouth from July to September. 



E. spinifera P. E. Muller. — Appears in June abundantly in the region between 

 Firth of Tay and W. Norway (Stadt) and Skagen, in the Skagerack and along the coast. 

 In July, August it was found from Skagen to the west of the Danish peninsula. In the 

 Skagerak it remains until October and along the coast until the middle of November. At 

 Plymouth rare in August. 



Podon Leiickarti G. O. Särs. ■ — June: rare west of the Danish Peninsula and in 

 the Skagerak. July: rare at the entrance to the Skagerak. 



P. intermedius Lilljeb. — July, August: more or less abundant west of the Danish 

 Peninsula, from the mouth of Elbe to Skagen, rare at Plymouth, more or less rare in 

 the Skagerak, where it remains until October, or along the coast to the end of that month. 



P. polypheinoides Leach. — Rare in August and September at Helder. 



Copepoda. 



Åcartia bifilosa Giesbr. — • November: from the E. Channel to Holland and the west 

 of Skagen. 



Å. Clausii Giesbr. — The whole year in the North Sea, in the Skagerak and at 

 Plymouth. January to April or May: rare at Plymouth and in the Skagerak. March: 

 in the North Sea, together with Halosphcera, common between the Shetlands and Norway. 

 West and south of Norway. South of the Dogger bank. East of Newcastle. June: 

 British east coast from Firth of Tay to Newcastle, common. From Holland to Heligoland. 

 Plymouth (maximum from the middle of May to the beginning of Septembej'). St. Vaast 

 la Hogue not rare. In the Skagerak not rare from the end of May or beginning of June to 

 October, November (maximum from the middle of August to the end of that month). 

 July, August: from the Channel to Skagen and above the Fisher Bank. November: the 

 E. Channel, Helder, Skagen to the south of Norway. South of the Orkneys. 



A. longiremis Lilljeb. — In the North Sea in March SW. of Norway and E. of 

 Newcastle, in Jime abundantly in the middle of the North Sea, 57° N. 3° E. and at 



