80 THE ENTOMOLOGIST. 
free from floods, and the spring of 1874 peculiarly early and dry. 
On the whole I am inclined to attribute the falling off in Canosa 
and other species to directly opposite causes. For many years 
Wicken Fen has been gradually becoming dryer, so much so that 
the sedge-crop now takes longer (I am informed) in coming to 
maturity than was once the case: may it not be this influence 
which, in stunting the luxuriance of the fen vegetation, is 
gradually rendering it unsuitable for the nourishment of the 
larve? It is not easy to find a good-sized reed (Arundo 
Phragmites) in the fen, except among those growing im the 
ditches, and this has a curious effect upon Macrogaster arundinis, 
which runs very small as compared with Yaxley specimens. 
I have seen one or two good-sized ones from Wicken, but most of 
them are exceedingly small, especially the females. It is 
interesting to find that this extraordinary insect does not appear 
to be decreasing in numbers: it is far from abundant, but I 
cannot learn that it ever was so at Wicken—certainly not in my 
recollection. It is, therefore, some comfort to think that 
although Cenosa be fast following in the steps of Nonagria 
concolor, we are at least likely to retain for this generation the 
most singular and interesting of the lepidopterous fauna of 
our fens. 
Chester Place, Norwich, December, 1878. 
A NEW MACRO-LEPIDOPTERA. 
By J. H. Tarecratt. 
NEpPTICcULA LAPPONICA, Wocke, A SPECIES NEW TO BRITAIN. 
T sent a short time ago some Nepticule, which appeared strange, 
to Mr. Stainton for identification, and he has just returned them 
as Nepticula lapponica, Wocke. They are closely allied to 
N. sorbi, but “have the fascia less oblique, more yellow, and 
generally broader.” The larve feed in broad serpentine mines in 
birch, are light yellow in colour when full fed, and are-to be found 
at the same time as N. betulicolella, viz., October Ist to 20th. 
[Nepticula lapponica appears to be either a scarce or over- 
looked species on the Continent, for Wocke only records it from 
Lapland and Finland. This makes Mr. Threlfall’s discovery 
especially interesting.— Eb. ] 
