26 P. T. CLEVE. THE PLANKTON OF THK NORTH SEA AND THE SKAGERAK. 



tember: M. -|-, V. r. Octoher: M. -|-, V. r. November: more or less sparingl)' N. of 

 Scotland and from 55°— 56° N. 1° E. -to S. Norway and W. of Jiitland; Vinga (30 m.) 

 not rare; V. r. December: V. rr. 



P. g-lobulus Stein. — July — August: rare above the Fislier Bank. November: N. of 

 Scotland rr; Sk. r. 



P. Michaélis Ehb. — July — ^August: W. and N. of Jutland r. November: N. of 

 Scotland rr; W. of the southern Norway r, Vinga (30 m.) rr; V. rr. 



P. oceanicuni Vanh. — May: M. not rai^e. July — August: the Shetlands (200—50 

 m.) r, W. of Jutland; M. r. December: V. rr. 



P. ovatum PoucHET. — April: from 57° N. 4° E. to Sk. common, hut sparingly from 

 the first named spöt to the Dogger Bank and the Dutch coast; rare W. of the Danish 

 Peninsula. June: the Shetlands, not rare. July — August: the Shetlands r, rather common 

 E. of the Firth of Tay. October: M. r. November: rare N. of Scotland and N. of Jut- 

 land; Vinga (30 m.) rr. 



P. palliduni Ostf. — February: 57° N. 6° E. rr. March: M. r. April: sparingly 

 from the Firth of Tay to Sk. and the W. of Schleswig; M. rr. May: M. r. June: V. r. 

 July — August: E. of Firth of Tay; M. r. September: M. r. October: M. r. November: 

 W. and N. of Scotland; from Holland to Skagen, always rare. 



P. pedunculatum Schutt. — November: sparingl}' from Holland to Sk. and at 56° — 



57° N. 4°— 5°E. 



P. pellucidum Bergh. — January: M. r. February: very rare at 58° N. 7° E. and 

 59° N. 1°E. March: from 56°33'N. 12° 16' E. to Måseskär r. ' April: from 57° N. 4° E. 

 to Sk. r; Skagerak and M. r. June: the Shetlands r. October: M. rr. November: very 

 rare at 57° N. 1°— 2° E. and N. of Jutland; Skagerak r. December: V. rr. 



Protoceratium reticulatuni {Peridinium ret. Clap. & Lachm. Protoc. aceros Bergh, 

 non P. reticidatum Schutt) — May: M. rr. 



Pyropliacus horologiura Stein. — February: at 58° N. 3° and 10° E. rr. July — 

 August: W. of Jutland -|-> M. r. September: M. r. October: M. and V. rr. November: 

 sparingly from S.W. Norway to the N- of Dogger Bank; rare N. of Holland. 



Prorocentnim micans Stein. — October: V. rr. November: N. of Scotland and N. 

 of Jutland. 



■' ' . " '; ' .' '.' Cystae. 



Pterosplifera Möbii Jörgens. (Pterosperma M. Ostenf.) ■ — January: M. r. Febru- 

 ary: rare in the area between 58° N. 3° E., 56° N. 4° E. and Sk.; M. rr. March: Vinga 

 r. April: from the Dogger Bank to Sk. r; V. rr. May: M. r, V. r. June: M. r. July 



