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president’s address. 
as a Zoaea, whose systematic position had been the subject of 
much dispute among Carcinologists, is shown to be the larval stage 
of an ordinary Crab. This is not merely advanced as an opinion, 
but its truth was demonstrated in the most satisfactory way by 
Thompson, who kept a Zoaea until it changed its skin, when it 
was found to have developed a set of appendages agreeing with the 
great chelae and the walking legs of a Crab, and further proved 
that the egg of the Edible Crab, Cancer pagurus, hatches out in the 
form of a Zoaea. In the same memoir he calls attention to the 
profusion of the minute floating animals of our own and other 
seas; and his statement that “the investigation of them holds out 
the promise of a rich harvest to the Naturalist, and a vast field of 
exploration replete with novelty and interest,” is one which may 
well be commended to the attention of the members of this 
Society. After explaining the ease with which this fauna may be 
obtained by means of a “small towing net of gause,” he makes 
the suggestion, which I think has been somewhat forgotten, that 
pelagic organisms might be collected by applying a net of this 
kind to the spouts of the sea-water pumps of a ship under sail. 
This method has been quite recently employed with great success 
by Professor Herdman and Mr. Gars tang.* 
In the fourth memoir (1830) Thompson discusses the systematic 
position of the Cirripedes or Barnacles, which he shows from their 
development to be undoubted members of the Crustacea. He 
remarks that the metamorphosis which occurs in these animals is 
scarcely less wonderful than that implied in the belief formerly 
current that Barnacles were the young or embryo-state of certain 
species of Geese ; a belief which, as he suggests, may have been 
connected with the instruction given in some Catholic countries to 
the “pious gourmet” that these Geese may be eaten during times 
of fasting and abstinence. This memoir contains an account of 
the Cypris-stage, or second larval form of Barnacles, and of' its 
metamorphosis into a small edition of the adult form ; and it 
finally disposes of the view that these animals are anomalous 
Molluscs. 
# See * Nature,’ vol. lvi., 1897, p. 555. 
