738 
THE VOYAGE OF H.M.S. CHALLENGES. 
a laminated structure, and were very compact and difficult to break up, being composed 
of felted masses of Eadiolarians and frustules of Diatoms. 
Pumice was very abundant in all the deposits, the trawl frequently bringing up 
numerous rounded pieces, many of them partly decomposed and coated with manganese 
peroxide. The mineral fragments in the deposits appeared to be chiefly derived from 
the pumice, except in the soundings close to the Japan coast. All the deeper deposits 
were brown or chocolate coloured, due to the presence of manganese. 
The dredgings and trawlings were not very productive. The dredge brought up 
from 1850 fathoms a large quantity of Globigerina ooze, specimens of Bothy actis 
symmetrica, Ophioglypha undulata, Ophiomusium corticosum, and Styraccister armatus, 
the latter being a new genus and species of Asterids. A specimen of Hyocrinus was 
obtained from 2325 fathoms, some fragments of Brisinga from 2300 fathoms, and a 
Discina was found on some pumice stones from 2425 fathoms. 
The surface fauna and flora were especially rich and abundant throughout. In the 
region of the Counter Equatorial Current, between the Equator and the Caroline Islands, 
pelagic Foraminifera and Mollusca were caught in great numbers in the surface nets, 
surpassing in this respect anything previously observed. The fact is most probably in 
relation with another, which may be pointed out. In this region the soundings in 2325 
and 2450 fathoms contained respectively 52 and 6 per cent, of carbonate of lime, 
whereas at 2300 fathoms, in lat. 14° 44 ; N., only a few broken fragments of Globigerina 
shells could be detected on microscopic examination; and at 2450 fathoms, in lat. 
19° 24' N., there was not a trace of carbonate of lime shells in the ooze. This shows 
apparently that where there are numerous calcareous shells at the surface their remains 
may be found at greater depths at the bottom than where relatively less abundant 
at the surface. The pelagic Foraminifera appear to float about in great banks ; one day 
immense numbers of Pulvinulina would be taken in the net, the next day Pullenia 
would be most abundant, and Pulvinulina nearly or quite absent from the hauls. 
The heavier shelled specimens were usually taken when the nets were dragged 100 
or 150 fathoms beneath the surface. Between latitudes 10° and 20° N., Oseillatorise 
were very numerous at the surface, and Diatoms, especially a large cylindrical 
Mmodiscus, were more abundant than in the tropical waters of the Atlantic far from 
land. The list of surface animals recorded in the note-book is nearly the same as that 
given on pp. 216 and 217, but the relatively much greater abundance of Radiolarians 
and Diatoms is specially noteworthy. 
Between the Admiralty Islands and the northern tropic very few birds were observed 
from the ship. One day, in lat. 5° N., a red-tailed Boatswain Bird (Phaethon jlavirostris) 
alighted on the ship, and the following day a Noddy Tern (Anous melanogenys) was pro- 
cured in a similar manner. As soon as the ship passed out of the tropics, she was daily 
surrounded by large numbers of the northern Albatross ( Diomedea brachyura). When 
