Microscopic Life in the Ocean at the South Pole. 567 



B. SILICEOUS PHYTOLITHARIA. 



11. Spongolithis aspera. 13. Spongolithis Fustis. 



12. ... cenocephala. 14. ... vaginata. 



3. Water from the equatorial ocean in direction of St. Louis in 



Brazil, in 0° lat., 28° W. long. 



A. SILICEOUS POLYGASTRICA. 



1. Fragilaria rhabdosoma. 2. Fragilaria Navicula. 



B. SILICEOUS PHYTOLITHARIA. 



3. Lithostylidium rude. 4. Lithostylidium Serra. 



4. Water from the Antilles Ocean, 24° N. lat., 40° W. long. 



A. SILICEOUS POLYGASTRICA. 



1. Haliomma radiatum. 



B. SILICEOUS PHYTOLITHARIA. 



2. Lithodontium nasutum. 4. Lithostylidium rude. 



3. Lithostylidium Amphiodon. 



C. MEMBRANOUS PORTIONS OF PLANTS. 



5. Pollen pini. 



It follows from these four series of observations obtained through 

 M. Schayer, that the ocean, in its usual condition, without pecu- 

 liarity of colour, without storms and other influences, contains, in the 

 most transparent sea-water, numerous perfect and wholly invisible 

 organisms suspended in it, and that the siliceous-shelled species are 

 the most predominant in all those cases, although the analysis of sea- 

 water does not show silica as a constant ingredient. 



III. On a Cloud of Dust which rendered the whole air hazy for a 

 long time on the high Atlantic Ocean in 1 7° 43' N. lat., 26° W, 

 long., and its being constituted of numerous siliceous animalcules. 



Mr. Darwin, the well-known and most meritorious English travel- 

 ler and writer on coral reefs, relates in the account of his travels, that 

 a fine dust constantly fell from the hazy atmosphere off the Cape 

 Verd Islands, and also on the high sea of that region, while he was 



