— 27 — 



and the Malay Archip. p. 24 ; Synedra Thalassiothrix Cleve, Bih. K. Sv. 

 Vet. Akad. Handl. 1, Nr. 13, p. 22, PI. 4, f. 24; Synedra sp., Chun, Aus 

 den Tiefen des Weltmeeres, Jena 1900, p. 206, f. 2, 3. 



Most of the present specimens are very delicate (f. gracilis Ostf.), 

 but also the main species has been met with. 



2 (it) - 4 (it) - 6(r) - 7 (it) - 10(-h). 



Area: Arctic and Northern Atlantic Ocean (especially in the Irminger Sea), 

 Antarctic Ocean from 20° W. to 91° E., Red Sea, Gulf of Aden, Indian Ocean 

 from c. 40" S. to 45° S., Malay Archipelago, Bering Sea. It is a bipolar species 

 which often predominates in the samples from the Subarctic regions. 



Naviculeae. 



Navicula Bory. 



76. N. membranacea Cleve, Phytoplankton 1897, 

 p. 24, Pl. II, f. 25-28 ; PI. f. the Red Sea p. 1033 ; 

 Atl. Plankt. Organisms p. 333 ; PI. f. the Indian Sea 

 and the Malay Archipelago p. 22 ; Lemmermann 1. c. 

 p 315. 



As supplement to the figures by Cleve (Phyto- 

 plankton) I have given two figures of a frustule in 

 valvular and in zonal view. No structure visible. 



2 (it) - 3 (rr) — 6 (rr) — 10 (rr). 



Area: Subtropical Atlantic Ocean (rare), Red Sea, Malay Archipelago, Cook 

 Strasse at New Zealand. 



Fig. 23. Navicula 

 membranacea 01. 

 Side view and front 

 view (IM), 



Nitzschieae. 

 Nitzschia Hass. 



77. N. seriata Cleve, Diat. of Vega, Vega-exped. vetensk. iakttagelser 

 PL 38, f. 75; Atl. Plankt. Organisms p. 335; A T . fraudulentà Cleve, Fish. 

 Board f. Scotland 1896, p. 300, PI. 1, f. 11; PL f. the Indian Ocean and 

 the Malay Archip. p. 22 ; Schröder, Neapel p. 32. 



1 (rr) - 2 (rr) - 6 (rr) — 10 (rr). 



Area: Arctic Ocean, Northern Atlantic Ocean southwards to Azores. Me- 

 diterranean, Malay Archipelago. 



4 — 8 — 190-2. 



