president’s address. 
237 
other hand, it. is nowhere otherwise than local and scarce, it is 
probably the remnant of an old fauna gradually giving way before 
other forms of life better fitted for the struggle for existence. 
When the area becomes very limited, and the stock small, inter- 
breeding may help to bring on the end, and various other causes 
no doubt contribute, at one of which I shall hazard a guess later 
on ; but in the present state of our knowledge, or rather ignorance, 
on the subject, all I can do is to place on record some scraps of 
information as to various species either extinct or threatening to 
become so. The typical insect fauna of our Fens may be divided 
into threo classes : — 
1. Those species which are confined to the old fen-lands of 
Huntingdonshire and Cambridgeshire. 
2. Those common to this district and to the Norfolk Hroads. 
3. Those confined to the latter locality. 
The second and third of these groups are both important and 
interesting, and it is eminently desirable that their life history and 
habits should be thoroughly worked out and recorded ; as, however, 
the risk of extermination is in their case not immediate, they do 
not come within the scope of my subject to-night. 
Nor can I deal with more than a very few of the first class within 
the limits of such a paper. I propose merely to bring forward 
a few notes relative to those species which have already become 
extinct, and, perhaps, one or two others more directly threatened, 
bearing in mind that the whole of this first group, being now 
almost entirely confined to the small area of Wicken Fen (about 
a square mile in extent), are in danger of extermination at no 
very distant time. I hardly realised, however, till I tried to put 
them together, how extremely meagre and unsatisfactory my notes 
were; and I now venture to introduce them, not so much for any 
value of their own, as in the hope of inciting some member, with 
more time at his disposal, to devote himself to the task before the 
opportunities are for ever lost. Already they are vanishing fast. 
Of the sources of information on this subject available to me in 
my younger days, incomparably the most valuable was that of 
intercourse and correspondence with the late Air. F. Fond and 
