98 THE DEPTHS OF THE SEA. [CHAP. ILI. 
In both of these last deep dredgings the dredge 
brought up a large number of extremely beautiful 
Polycystina, and some forms apparently intermediate 
between Polycystina and Sponges, which will be 
described shortly. These organisms did not seem to 
be brought from the bottom, but appeared to be sifted 
into the dredge on its way up. They were as numerous 
adhering to the outside of the dredging-bag as within 
it. During the soundings taken near this locality 
quite a shower of several beautiful species of the 
Polycystina and Acanthometrina fell upon the chart- 
room skylight from the whole length of the sounding- 
line while it was being hauled in. 
We were now steaming slowly back towards the 
coast of Ireland; and on Monday, July 26, we 
dredged in depths varying from 557 to 584 fathoms 
(Stations 39-41) in ooze, with a mixture of sand and 
dead shells. In these dredgings we got one or two 
very interesting aleyonarian zoophytes, and several 
ophiurideans, including Ophiothria fragilis, Amphiura 
ballii, and Ophiacantha spinulosa. Many of the 
animals were most brilliantly phosphorescent, and we 
were afterwards even more struck by this phenomenon 
in our northern cruise. In some places nearly every- 
thing brought up seemed to emit light, and the mud 
itself was perfectly full of luminous specks. The 
aleyonarians, the brittle-stars, and some annelids 
were the most brilliant. The Pennatule, the Virgu- 
larie, and the Gorgonie shone with a lambent white 
light, so bright that it showed quite distinctly the 
hour on a watch; while the ight from Ophiacantha 
spinulosa was of a brilliant green, coruscating from 
the centre of the disk, now along one arm, now along 
