2 Mr. R. M‘Lachlan’s Monograph of the 
taking a work of this kind to Dr, Hagen, he has at all times 
taken the warmest interest in it, and his assistance has been in- 
valuable owing to his power of discriminating the often minute 
structural characters, so subtle yet so decisive, to be found in 
the Trichoptera, and to the opportunities he has had of investi- 
gating the types of the species described by previous authors ; 
it is to be regretted that most of these have ignored the existence 
of structural specific characters, more difficult to investigate than 
mere differences of coloration, but far more certain. 
With respect to the synonymy,* I have endeavoured to make 
it as complete as possible, and have indicated by an asterisk in 
brackets—thus, (*)—all citations that I have been able to verify 
by an actual examination of type-specimens, a plan that it would 
be desirable to adopt more frequently in similar works. The 
types of many of Pictet’s species are now lodged in the British 
Museum, and have been carefully examined both by Dr. Hagen 
and myself. I have also a considerable number of species named 
by Dr. Brauer, contained in the Collection of European Neuroptera 
formed by Professor Zeller, which is now in my possession. 
The Collection of Curtis was inspected by me several times be- 
fore it was sent to Australia, and that of Stepheus has been con- 
stantly consulted. The papers by Dr. Hagen, revising the species 
of Pictet (published in the Stettin “ Entomologische Zeitung’’), and 
of Rambur (published in the ‘‘ Transactions de la Société Ento- 
mologique Belge’), have been carefully studied, and I have had at 
all times the benefit of a constant correspondence with the author 
on difficult points. Still much remains to be done, and it is pos- 
sible that many of the citations here given may prove erroneous, 
when they can be tested by an examination of typical specimens. 
Many of the species described in the works of Zetterstedt and 
Kolenati stand greatly in need of identification in this manner. 
I will now proceed to compare the number of species described 
in this Monograph with those noticed by previous authors as 
occurring in this country. Passing over Stephens’ * Catalogue” 
and Curtis’ Guide” as being mere lists of names, I come to 
* Since this was written I have received a copy of Dr. Hagen’s “ Phry- 
ganidarum Synopsis synonymica,” just published in the ‘‘ Verhandlungen 
der k. k. zoologisch-botanischen Gesellschaft in Wien.’’ This work is a 
laboriously compiled list of the described Trichoptera of the whole world. It 
will be found that the synonymy of our species agrees very nearly with 
that given in this Monograph. Some few discrepancies occur, which time 
and further knowledge will perhaps clear up. Many of the citations from the 
old authors will always remain uncertain. 
