REPORT ON THE DEEP-SEA DEPOSITS. 
223 
the Arabian Sea and Bay of Bengal in the north and into the Southern Ocean in the 
south. 
In the Pacific Ocean, the area covered by Globigerina Ooze is estimated at about 
14,800,000 square miles. In the western basin of the Pacific it extends from the 
Southern Ocean, in about 55° S. latitude, along the shores of New Zealand and Australia, 
in a very irregular and broken manner, to the eastern shores of Japan in the north ; 
there is a detached area in the Central Pacific around the Society Islands, a smaller 
area extending north-west from the Sandwich Islands, and numerous small detached 
patches around the coral island groups. In the south-eastern part of the Pacific, Globi- 
gerina Ooze extends westwards from off the Chilian coast of South America, encircling 
an extensive area of Red Clay, and joins the area of the western basin south-east of New 
Zealand, so that it may be said to extend almost uninterruptedly from the shores of 
Japan to the south-west coast of South America. 
An examination of the bathymetrical contour hues on Chart 1 shows that the 
Globigerina Oozes occupy all the medium depths of the ocean removed from continents 
and islands, and is especially developed in those regions where the surface of the sea is 
occupied by warm currents, the only development of the deposit in the Arctic regions being 
in the track of the northern extension of Gulf Stream waters, where in the Norwegian Sea 
this deposit is estimated to cover about 193,000 square miles, the greater part of which 
is within the Arctic Circle. It will also be noticed that the deposit is found at greater 
depths in tropical regions than in more northern or southern latitudes. 
Pteropod Ooze. 
This name was employed by Mr. Murray during the cruise of the Challenger to 
designate those deep-sea deposits in which a very large part of the calcareous organisms 
consists of the dead shells of Pteropods and Heteropods, along with the shells of other 
pelagic and larval Molluscs. One of the most remarkable facts discovered by the Chal- 
lenger is, that though the remains of these pelagic Molluscs are abundant everywhere in 
the surface waters of the tropical and subtropical regions of the ocean, yet their dead 
shells are wholly absent from the deposits in all the deeper waters. A few traces of 
them may be met with occasionally in depths as great as 2000 fathoms, but it is only in 
lesser depths that they make up any appreciable part of a Globigerina Ooze, or are so 
abundant as to justify the distinctive name of Pteropod Ooze. As in the warmer regions 
the appearance of Pteropod and Heteropod shells in a deposit is associated with a depth 
limit and other oceanic phenomena of great interest, it seemed desirable to emphasise 
their occurrence in this way. A Pteropod Ooze is then distinguished from a Globigerina 
Ooze, with which it has so many points of resemblance, by the presence of these shells. 
The following is a list of the Pteropod and Heteropod shells that may be found in a 
Pteropod Ooze ; — 
