Microscopic Life in the Ocean at the South Pole. 563 



The chief mass was densely crowded with Fragilaria pinnulata 

 and with Coscinodiscus, which on softening in water generally exhi- 

 bited their green ovaries, perhaps originally brown. 



5. Contents of the stomach of a Salpa, 66° S. lat., 157° W. long. 



1842. 



SILICEOUS POLYGASTRICA. 



1. Actiniscus Lancearius. 8. Dictyocha aculeata. 



2. Coscinodiscus Apollinis. 9. ... Speculum. 



3. ... cingulatus. 10. Fragilaria acuta. 



4. ... gcmmifer. 11. ... granulata. 



5. ... lineatus. 12. ... rotundata. 



6. ... Lunce. 13. Helionyx duodenarias. 



7. ... subtilis. 14. Pyxidicula. 



This material contained a large number of Dictyochas, which evi- 

 dently must have been particularly sought for by the Salpa, since 

 they do not occur in the other samples, and consequently appear to 

 be a favourite food of the Salpa. 



6. Flakes floating on the surface of the ocean in 64° S. lat., 160° 



W. long. 



They are like the Oscillatorice of our waters, matted with delicate 

 fibres and granules interspersed through the mass. The chief sub- 

 stance is formed of siliceous, very delicate, lateral tubes of the quite 

 new and peculiar genus Chcetoceros. The nature of the granules 

 remains doubtful. The other forms are scattered through this mat- 

 ted substance ; all exhibit however their dried-up ovaries, and con- 

 sequently were collected alive. 



SILICEOUS POLYGASTRICA. 



I. 



Asteromphalus Darwinii. 



10. 



Dictyocha aculeata. 



2. 



... 



Hookerii. 



11. 



Binoculus. 



3. 



... 



Rossii. 



12. 



Ornamentum 



4. 



... 



Buchii, 



13. 



Speculum. 



5. 



... 



Humboldtii. 



14. 



Fragilaria Amphiceros. 



G. 



ClIETOCEROS 



Dichceta. 



15. 



granulata. 



7. 



... 



Tetrachceta. 



16. 



Hemiaulus obtusus. 



8. 



Coscinodiscus lineatus. 



17. 



Litliobotrys dcnticidata. 



9. 



... 



subtilis. 







