320 THE ATLANTIC. [chap. v. 



W. Depth, 1900 fathoms. Bottom temperature, 1°"9 C. Chemical 

 composition : 



Loss on ignition after drying at 230'' F 6'63 



^'"™^"^-- [5-86 



Ferric oxide ) 



Calcium phosphate Small traces 



Calcium sulphate 0'51 



Calcium carbonate 'Zi'SU 



Magnesium carbonate 1"2'7 



(Jeneral residue, consisting of soluble silica with the insoluble silicates ir23 



100-0(t 



A globigerina ooze, containing many pelagic foraminifera of the gen- 

 era Glohigerina, Hartigerina, Pulvinulina, Sphceroiditia, and Orbulina ; 

 many coccoliths and rhabdoliths. A few pteropod shells and valves of 



Ostracoda, and otolites of fishes. Amorphous clayey matter and small 



mineral particles — mica, quartz, olivine, feldspar, and pumice. Some of 

 the particles of quartz were rounded as if wind-blown. 



No. 11.— Station XIV. March 5th. Lat. 21° 1' N., Long. 46° 29' 

 W. Depth, 1950 fathoms. Bottom temperature, 1°'8 C. Chemical 

 composition : 



Loss on ignition after drying at 280° F 4-58 



Alumina ) 



Ferric oxide \ 



Portion soluble in Calcium phosphate 1-12 



hydrochloric acid \ Calcium sulphate 1-20 



= 90'82. Calcium carbonate 79'17 



Magnesium carbonate 1 -40 



Silica 4'(')(i 



Portion insoluble 1 



. , , , , . 1 Insoluble residue, principally alumina and ferric oxide, 



in h\'drochloric > . . . > i i . > 



. , . „„ I vvith silica 4-60 



acid = 4-60. J 



lOO-OO 



A reddish globigerina ooze, containing many pelagic foraminifera of 



the usual genera, and many coccoliths and rliabdoliths. Amorphous 



clayey matter with oxide of iron ; many small particles of sanidine, 

 augite, bornblende, and magnetite. 



No. 12.— Station XV. March 6th. Lat. 20° 49' N., Long. 48° 45' 

 W. Depth, 2325 fathoms. Bottom temperature, l^'V C. Chemical 

 ■composition : 



