80 
THE VOYAGE OF H.M.S. CHALLENGER. 
Grey Ooze and Grey Mud usually indicate an intermediate condition between 
Globigerina ooze and Red Clay ; or in some cases a fine-grained grey deposit, formed in 
deep water, chiefly of land debris. [The microzoic remains indicate a fauna in all 
respects similar to that of a Globigerina ooze]. 
In tropical and sub-tropical regions, in depths less than 2000 fathoms, the shells of 
Pteropods and other pelagic Mollusca are generally present in considerable numbers in the 
oceanic deposits. In depths less than 1500 fathoms, far from land, these molluscan 
remains appear to furnish fully one-half of the carbonate of lime, and they impart a 
distinct character to the sea-bottom. To calcareous deposits of this sort the name 
Pteropod Ooze has been applied. The Challenger met with typical examples of Pteropod 
ooze at depths of 1240 fathoms and 1415 fathoms in the South Atlantic, on the ridge 
between Tristan d’Acunlia and Ascension Island. 
The Stations enumerated refer to areas explored on several distinct expeditions, which 
are taken in the following order: — I. Challenger Expedition; II. “Porcupine” Expedi- 
tion; III. “Knight-Errant” Expedition; IV. Arctic Seas, visited on the last British 
North-Polar Expedition, and the Austro-Hungarian North-Polar Expedition. 
I. Challenger Expedition. 
It may be useful at the outset to describe in a few sentences the general track of the 
Challenger cruise. 
Leaving Portsmouth, the vessel proceeded down the coast of Spain and Portugal to 
Gibraltar, sailed thence for Madeira and the Canaries, and across the Atlantic to Sombero 
and Culebra, the outermost of the West Indian Islands ; from this point northwards to 
Bermuda, and thence to Halifax, Nova Scotia. 
Returning to Bermuda, the Atlantic was again crossed on a more northerly line than 
previously, by way of the Azores, as far as Madeira. From Madeira the vessel was 
turned southwards to the Cape de Yerde Islands, and down the African coast to within 
about four degrees of the Equator ; then in a more westerly direction, crossing the Line 
at about long. 31° W., to Pernambuco and Bahia, touching at St. Paul’s Rocks and 
Fernando Noronha. From Bahia the South Atlantic was traversed to the Cape of 
Good Hope, stopping at the Island of Tristan d’Acunha on the way. 
From the Cape to Melbourne the course taken was first to Kerguelen Island, and 
then still further south, reaching the Antarctic Circle at about long. 80° E. 
After leaving Melbourne the Challenger proceeded to Sydney, thence to New 
Zealand, and by Cook Strait and the Kermadec Islands to Fiji ; from Fiji through 
Torres Strait, and west of the Philippine Islands to Hong Kong. After a short stay at 
