THE DEPOSITS OF THE SEA-BOTTOM. 



21 



In the first group the instances are too few to deduce more common results from them; of the 

 three last groups we get the following average: 



Of this last table it will be seen how the coarser ingredients of the specimen, as was to be 

 expected, decrease very much when we get farther from the land, while on the contrary the ingredients 

 under o-02 mm keep at about the same percentage in all three species of deposits; this is caused by the 

 fact, that these finest ingredients at the same time decrease in proportion to the carbonate of lime, and 

 increase in proportion to the other mineral ingredients, which two influences tolerably well counter- 

 balance each other. If we calculate the percentages of the different sizes of grains without regard to 

 the carbonate of lime we get the following numbers: 



Gray deep-sea clay 

 Transition clay . . 

 Globigerina clay . 



Over 0-5"™ 



4-27 

 4-12 

 i-66 



0-5— 0-05" 



30-27 



I7-75 

 12-05 



0-05 — O-02"' m 



u-54 

 9'94 

 8-12 



Under o-Q2 mm 



53-92 

 68-19 

 78-17 



From this is seen how the coarser ingredients in the two first columns decrease with more 

 than half the amount from the Gray deep-sea clay to the Globigerina clay, while the ingredients from 

 0-05 — o-02 mm only decrease very slightly, and the finest particles increase very much. Of all the 



