183 
by being suffocated, their death and decay would help to make 
the conditions still more unfavourable, and bring about the 
destruction of others in the immediate neighbourhood. All along 
the shores, after the red colour had disappeared, abundant evidence 
was visible to shew that most of the organisms had been killed 
by secondary causes chiefly due to the presence of the putrid 
bodies of the oysters and mussels. At Watson’s Bay and at 
Vaucluse Point, although the red colour was not noted to the 
same extent as at other places, the effects produced were equally 
destructive, and the stench from the mussel beds at the former 
place was almost unbearable. I received a bottle of water from 
Yaucluse, and with it a note to the effect that the discoloured 
water had not been observed there, and yet the oysters were 
dying just as in other parts of the harbour. On examining the 
water, which appeared to the eye quite clear and free from 
impurities, I found the Glenodinium present in considerable 
quantity. 
The Glenodinium appeared to be almost confined to the surface 
of the water and to swim in lines or clouds, not only in the harbour 
but also when seen in a bottle ; and if placed near a light it 
invariably collected at the point at which the light was most 
intense. It is therefore probable that the fauna in the deeper 
parts of the harbour would escape or be only slightly affected. 
The area of surface water more or less discoloured by the presence 
of the Glenodinium is rather difficult to estimate, it was observed 
in nearly all the bays and inlets throughout Port Jackson, and I 
was told that Mr. H. Prince saw a large patch of red water about 
two miles off Manly, and which was about a mile in length. I 
also obtained specimens at Coogee and Maroubra, which shew 
that it existed in greater or less number for some distance along 
the coast. 
The species enumerated in the following list have been obtained 
during the author’s visits to various localities in Port Jackson 
and the neighbourhood ; they were mostly taken in the tow-net. 
Amongst them is the one which I regard as a new species ( Gleno- 
dinium rubrum ), and two previously known to occur only in fresh 
water, namely, Geratium hirundinella and Anurea cod dear is. The 
latter is found in ponds near Sydney, while the former as well 
as the twenty-nine additional species have not hitherto been 
recorded from Australian waters : — 
PROTOZOA. 
Grade CORTICATA, Lankester. 
Class DIN OFLAGELLATA, Butschli. 
Order ADINIDA, Berjh. 
Family Pborocentbina. 
