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president’s address. 
Few spots in the country, I should imagine, have been more 
worked than Wicken Fen. It is only about a mile square, and 
for several years entomologists have visited it frequently, besides 
two or three local collectors, one at least of whom (a resident 
shoemaker named Houghton) has done excellent work. I have 
myself seen five large attracting lamps all in operation at the 
same time in the Fen, forming a regular lighted street, which we 
called “Rotten Row.” That an insect so much sought after as 
extrema should have been there undiscovered till now would be 
indeed extraordinary, yet I should not venture to call it impossible. 
Some Moths seem to linger on in extremely small numbers 
in a spot, not actually dying out, but only detected at long 
intervals. Thus Hydrilla palustns has never been known in 
this country save as an extreme rarity. Single specimens were 
taken; the first by Mr. Allis, in Yorkshire, about 1858, then at 
Quy Fen (Cambs) in 1862; and at a gas lamp on the Newmarket 
Road, in this city, by Mr. Barrett, in 1869. While collecting 
with light at Wicken Fen in June, 1877, I secured one specimen 
of this rarity, and lost another owing to the sudden extinction of 
my light (a magnesium lamp). Two others were taken in the Fen 
that year. Next season several collectors worked hard for this 
insect, and I think that fifteen in all were secured, of which two 
fell to my lot. In the following season three more were taken ; 
but from that time to this I have heard of only two captures, 
the last more than ten years ago. 
Of the species that survived the drainage of the old fen-land, 
but are now on the verge of extinction, I would place first Orgyia 
ccenosa, the Whittlesea Ermine. This insect was so abundant at 
Whittlesea Mere as to be thought unworthy of record ; hence I can 
find no details as to its earlier captures. In Wicken Fen it was 
also abundant ; the sedge-cutters regularly supplying the larvae and 
pupae in any number, as Mr. Brown informed me, at a shilling 
a dozen. This price was ultimately raised to three shillings 
a dozen ; and about 1865 the supply altogether fell off. My first 
visit to Wicken was in 1872, when I learned that in the previous 
season two larvae had been found. In 1873 I devoted some time 
