5 
leases at that time. No visit was made by me for the purpose of 
investigating the matter. During the early part of September, 
Fisheries Inspector Latta brought in a specimen of an oyster (fromm 
a lease in the Hawkesbury River) which was in the last stage of 
destruction by one of these flat worms, and which contained the 
worm itself. This specimen had been handed to Mr. Latta by 
Mr. J. Izzard, who had stated that the worm was very plentiful on 
his leases at Bar Island and Pelican Island, and that apparently 
it was destroying the oysters. Upon this, it was so arranged that I 
made a short visit to the locality in question, for the purpose of 
obtaining more definite information. At Bar Island I found the 
Wafer present in large numbers, and some were found actually at 
work between the valves of the oysters. Large numbers of gaping 
shells of oysters only recently killed were to be seen on all hands, 
while the same was apparent on Pelican Island (which is submerged 
at high water). In view of the very positive evidence obtained at 
the time, it is only fair to assume that at least a part of these—if 
not all, probably a very large percentage—had succumbed to the 
attacks of the Wafer. I must here point out that, although the com- 
mon oyster worm (Polydora or Leucodore) was only too abundant on 
portions of these leases, none of the recently dead and gaping shells 
which I examined showed the least sign of its attacks, or of the 
attacks of the common “ Drill’ or “ Borer ’’ (Vrosalpinz), although 
I found the latter (previously unrecognised from this locality) to 
be fairly plentiful. 
It is of interest to mention that, at the time of my visit, the 
oysters were all “opening very badly ”’—that is, they were in poor 
condition, and were likely to remain so until the advent of a 
freshet in the river. 
Method of attack.—After gaining an entrance between the valves 
of the oyster, the Wafer proceeds to wrap itself round the upper 
part of the oyster, as close to the great adductor muscle (which so 
powerfully keeps the two shells shut) as it can get. It then proceeds 
to pour out a great amount of thick, stringy, slimy mucus, which 
perhaps has the effect of partly digesting the body of the oyster, so 
as to prepare it for absorption by the Wafer. Certainly in those 
which have come under my notice, the adductor muscle, usually the 
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