50 P. T. CLEVB, PLANKTON-RESEARCHES. 



Leptocylindvus dauicus Cleve. — 1901 January, V. roo. Marek, V. oro; M. r. 

 April, M. orr. May, V. + oo. October, V. + r. November, 57° N. 3° E. r, Skagen r. V. + ro. 

 1902 Mardi, V. oor. iV/aj/, N. of Jatland r. Y. oro. — ? Åhi. 



Lithodesmiuui imdulatiim Ehrenberg. — 1901 November, mouth of the Elbe. — 

 Nm or rather litoral. • 



Navicula membranacea (Jleve. — 1901 November, sparingly from Scotlarid to Ska- 

 gen. December, M. roo. R.Sg. r. 



1902 February, 5(3°— 57° N. 6°— 7° E. r. — Nm. 



Navicula Yanhöifeni Gran. — 1901 April, Nonv. 69° N. 14°— 18° E. +. — Ng. 

 Nitzsclua delicatissima Cleve. — 1901 May, Atl. 63° N. 3° W. c. — ? T. 



Nitzschia seriata Cleve. — 1901 February, V. oor. March, V. rrr. M. r. April, 

 V. oro. M. r + r. ^ov\v. 69° N. 14°— 18°E. + to c. May, Atl. 6.^° K 2°— 3° W. c. +, 

 68° N. 13°E. r. November, Skagen r. V. oro. December, V. roo. 



1902 February, N. of Jutland r. x\long the coast of Sweden r. March, V. rr +. 

 M. roo. Ajyril, M. ro. May, at 57° N. 2° E. r. — ? T (Cha4oplankton). 



Rhizosolenia alata Brightvvell. — 1901 February, Norw. 63° — 64° N. 2° E. r. 



October, V. orr. M. oro. November, area between 56° — 57° N. 1° E., N. JutJand and 55° 

 N. 6° E., as a rule sparingly, but cornmon in some spöts W. of Jutland. V. r + r. M. r. 

 December, V. + oo. — S. , , ■ 



Rhizospleuia calcar aAås Schulze. — 1901 January, V. + oo. November, W. of the 

 Danish Feninsula r. V. oor. December, R.Sg. r. 



1902 January, V. r. February, Vinga 85 — 50 m. r. Central Gullmarfjord 80 — 50 

 in. r. — Nlm. 



Rhizosolenia Debyana Peragallo. — 1901 February, Norw. 64° N. 0° — 1° E. r. 



(Gran.) 



Rhizosolenia delicatula Cleve. — 1901 January, V. oro. May, Atl. 68° N. 13° E. r. 



August , very rare off Holland. 



1902 February, JST. of Jutland r. — Nm. 



Rhizosolenia gracillima Cleve. — 1901 January, V. + ro. June, M. o +. July, 

 M. oro. August, very cornmon E. of the Orkneys and W. of Jutland to Skagen, thence 

 to 58°20' N. 10°5' E., M. and Vinga. September, V. r. October, oo +. November, V. oro. 

 December, V. oro. M. roo. R.Sg. r. Nh. +. 



