MARINE ALGAE 



INTRODUCTION 



Among the numerous plankton collections made by 

 the Carnegie, a few contained algae of large size, making 

 up the macroscopic, floating population, some species of 

 which, particularly Sargassum natans (L.) Meyen (better 

 known as Sargassum baccllerum [Turn.] C. Ag.) and S. 

 fluitans Boerg. seem to become members of true self- 

 perpetuating pleuston formations. Of such collections, 

 some twenty-six bottles of various sizes were placed in 



the hands of the author for examination and report, all 

 of which except one (bottle 1798) contained at least some 

 minute fragment of the larger marine algae. The col- 

 lections were gathered from the North Atlantic and the 

 South Pacific oceans. The three samples (nos. 309, 317, 

 and 318) from the neighborhood of Easter Island in the 

 Pacific Ocean and bottle 8169, from Apia, Samoa repre- 

 sent localities south of the equator. 



Sargassum fluitans Boerg. 



* Approximately 



ATLANTIC COLLECTIONS 



The majority of the samples show, as might be ex- 

 pected, fragments of the two most common Sargasso 

 weeds of the floating types, Sargassum natans (L.) Meyen 

 and S. fluitans Boerg., both of which are usually desig- 

 nated as Sargassum bacclferum (Turn.) C. Ag. Although 

 scraps (at times a single vesicle) are not always cer- - 

 tainly to be identified as to the one or the other species, 

 most of these samples seem fairly clear as to distinc- 

 tion. 



In the neighborhood of station 6, latitude 50° 22' 

 north and longitude 13° 31' west, off the coast of Ireland, 

 the dip net (sample 38, bottle 4011) brought up floating 

 Ascophyllum nodosum (L.) Le Jolis, or "bottle wrack." 

 North from this, on the way to station 7, off the Faroes, 

 the 1/2 meter net caught more of this species (sample 



51, bottle 3040, June 6, 1928) on which there was abun- 

 dant epiphytic Scytosiphon lomentarius (Lyng.) J. Ag. 

 There were also 2 or 3 large fragments of Fucus vesl- 

 cnlosos L. and on this was considerable epiphytic 

 Pylaiella litoralis (L.) Kjellm. Sample 51 also showed 

 as epiphytes, excellently developed specimens of Entero- 

 morpha crinita (Roth) J. Ag., a widely spread species 

 closely related to, if not identical with, E. plumosa 

 Kuetz. On June 4 (sample 49, bottle 4074) the 1/2 meter 

 net caught from the surface a single bladder of Asco- 

 phyllum. 



The Atlantic collections present nothing except what 

 was to be expected. The data are given for reference as 

 to floating conditions and possible depth relations. 



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