Prof. W. Thomson on [June 18, 



tides (some dark-coloured and some clear) of Foramiuifera, species of 

 Orbulina, Globigerina, aud Pulvinulina, a pretty species of Uvigerina, 

 Planorbulina, Miliolina, JSulimina, and Nummulina. There were very 

 few Diatoms. 



"In the deep soundings and dredgings before reaching the Crozets, in 

 1900, 1570, and 1375 fathoms, the bottom was composed entirely of 

 Orbulina^ Globiyerina, and Pulvinulina, the same species which we get on 

 the surface, but all of a white colour and dead. Of Foraminifera, which 

 we have not got on the surface, I noticed one Rotalia and one Polysto- 

 mella, both dead. Some Coccoliths and Ehabdoliths were also found in 

 the samples from these soundings. On the whole, these bottoms were, I 

 think, the purest carbonate of lime we have ever obtained. "When the 

 soundings were placed in a bottle and shaken up with water, the whole 

 looked like a quantity of sago. The Pulvinulince were smaller than in 

 the dredgings in the Atlantic. We had no soundings between the Cro- 

 zets and Kerguelen. 



" The specimens of the bottom about Kerguelen were all from depths 

 from 120 to 20 fathoms, and consisted usually of dark mud, with an 

 offensive sulphurous smell. Those obtained furthest from land were made 

 up almost entirely of matted sponge-spicules. In these soundings one 

 species of Eotalina and one other Foraminifer occurred. 



" At 150 fathoms, between Kerguelen and Heard Island, the bottom 

 was composed of basaltic pebbles. The bottom at Heard Island was much 

 the same as at Kerguelen. 



" The sample obtained from a depth of 1260 fathoms, south of Heard 

 Island, was quite different from any thing we had previously obtained. 

 It was one mass of Diatoms, of many species ; and, mixed with these, 

 a few small Globigerince and Badiolarians, and a very few crystalline par- 

 ticles. 



" The soundings and dredgings while we were among the ice in 1675, 

 1800, 1300, and 1975 fathoms, gave another totally distinct deposit of yel- 

 lowish clay, with pebbles and small stones, and a considerable admixture of 

 Diatoms, Eadiolarians, and Globigerince. The clay and pebbles were 

 evidently a sediment from the melting icebegs, and the Diatoms, Eadio- 

 larians, and Foraminifera were from the surface-waters. 



" The bottom from 1950 fathoms, on our way to Australia from the 

 Antarctic, was again exactly similar to that obtained in the 1260-fathoms 

 sounding south of Heard Island. The bottom at 1800 fathoms, a little 

 further to the north (lat. 50 1' S., long. 123 4' E.), was again pure 

 ' Globiyerina-ooze,' composed of Orbulince, Globiyerince, and Pulvinulince. 



"The bottom at 2150 fathoms (lat. 47 25' S., long. 130 32' E.) was 

 similar to the last, with a reddish tinge ; and that at 2600 fathoms (lat. 

 42 42' S., long 134 10' E.) was reddish clay, the same which we got at 

 like depths in the Atlantic, and contained manganese nodules and much 

 decomposed Foraminifera." 



