Reviews—Dr. John Murray—On Marine Deposits. 515 
recent dredgings off the east coast of Africa for the purpose of laying 
cables, have furnished the author with ample means for extending 
the results formerly attained; and, on the present occasion, Dr. 
Murray ventures to map the area ‘described, carefully marking all 
the points from which sediment has actually been examined, and 
those from which sufficient material has been obtained for a chemical 
and microscopical analysis. The map “represents the Indian Ocean 
and those portions of the Southern and Antarctic Oceans between 
the meridians of 20° and 150°H., and is estimated to contain 
27,600,000 square miles.” In this area, 415 reliable soundings in 
depths of 1000 fathoms and upwards are available for study and 
comparison; and the descriptions and conclusions detailed in the 
memoir before us form an important addition to the quota of infor- 
-mation concerning marine sediments already placed by Dr. Murray 
at the disposal of geologists. 
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“Beyond the 1000-fathom line there is a gradual deepening from 
the shore, extending southwards and eastwards, the deeper soundings 
being found in the eastern portion of the region under consideration. 
The deepest part is, indeed, situated between the equator and the 
