780 
THE VOYAGE OF H.M.S. CHALLENGER. 
state of growth. So irregular was the ground out to 35 fathoms that dredging was 
almost, if not quite, impossible ; still by means of the swabs and tangles some corals 
were obtained. From 35 or 40 fathoms down to 150 fathoms dredging was equally 
difficult. Here a number of Sponges, Alcyonarians, Corals, and other invertebrates were 
obtained. Beyond 150 fathoms the bottom was a coral sand with volcanic minerals and 
pelagic shells. The soundings taken by the ship at depths of 420, 590, 620, and 680 
fathoms showed the presence of a volcanic sand or mud, containing coral debris, fragments 
of Pteropods, Gasteropods, Coccoliths, with pelagic and other Foraminifera ; the deposits 
at the greater depths contained about 19 per cent, of carbonate of lime. 
Fathoms 7 so 22s 200 n s iso 1 ts too 7 s so 7s 0 
Mr. Moseley says that in from 20 to 30 fathoms a Mycedium and a Madrepora were 
obtained different from those on the reefs and in shallow water. In from 30 to 70 
fathoms were found the same Mycedium, a fragment of Madrepora (both probably from 
the former depth), and a small solitary Balanophyllia, which from its appearance very 
probably came from 50, 60, or 70 fathoms. Also in from 30 to 70 fathoms 
Alcyonarians and Sponges were obtained. One of the Alcyonarians is very hard, and 
looks like a Coral ( Porites ), but is seen in section not to be one. There were also several 
pieces of the Mycedium, a bit of the Madrepora, and several specimens of the 
Balanophyllia. There was also another calcareous organism forming large thin 
