On Oceanic Deposits examined. 471 



II. "Preliminary Reports to Professor Wyville Thomson, F.R.S., 

 Director of the Civilian Scientific Staff, on Work done onboard 

 the 'Challenger/" By John Murray, Esq., Naturalist to the 

 Expedition. (Published by permission of the Lords of the 

 Admiralty.) Received Feb. 14, 1876. Read March 16. 

 [Plates 20-24.] 



Page 



1. Preliminary Report on Oceanic Deposits 471 



2. Preliminary Report on some Surface Organisms and their relation to Oceanic 



Deposits 532 



3. Preliminary Report on Yertebrates 537 



Preface to Preliminary Reports. 



The Preliminary Reports have been prepared at the request of Professor 

 "Wyville Thomson. They have been compiled during the past three weeks 

 from notes taken daily during the past three years. In only a few cases 

 has it been possible to refer to the objects remarked upon, they having 

 been sent home for greater safety, or packed away beyond reach. When 

 specimens taken early in the cruise can be placed side by side and com- 

 pared with the more recent revelations of the trawl, dredge, or sounding- 

 tube, many of the statements herein made may require to be modified. 



Reports on three years' work, prepared under the disadvantages above 

 mentioned, must necessarily be very incomplete ; and indulgence may 

 be asked till the final Report can be issued. 



To all my coadjutors, naval and civilian, I am indebted for much 

 assistance, especially to Mr. Wild for his drawings, to Mr. Buchanan for 

 much information concerning the chemical constituents of the bottoms, 

 and to Professor Thomson for assistance and advice, not only in pre- 

 paring these Reports, but also while carrying on the investigations of 

 which they are intended to give some account. 



JOHN MURRAY. 



Valparaiso, Chili, 

 9th December, 1875. 



1. Preliminary Report on Specimens of the Sea-bottoms obtained in the 

 Soundings, Dredgings, and Trawlings of H.M.S. ' Challenger/ in the 

 years 1873-75, between England and Valparaiso. 



Method of Work. — During the first six months of the expedition the 

 sounding-apparatus in use on board was provided with a very narrow 

 cylinder, which brought up only a very small quantity of the bottom. 



In July 1873 Capt. Nares had a much larger cylinder fitted to the 

 instrument, one with a 2-inch bore ; and later on he caused the weights 

 to be so arranged with respect to the cylinder that the latter projected 

 some 18 inches beneath the former. 



This arrangement, the cylinder of which is always provided with the 

 common butterfly-valve, usually gives us a very large quantity of the 



