4 Mr. R. M‘Lachlan’s Monograph of the 
can promise them that the delights to be derived from the study 
will amply repay them for the Jabour bestowed upon it; and I 
feel assured that those who seriously occupy themselves in the 
study of the Z’richoptera, will be the most ready to excuse the 
omissions and imperfections of this Monograph. 
Characters of the Order. 
Antenne setaceous, multiarticulate. Ocelli three or none. Man- 
dibles rudimentary (or absent ?). Maxillary palpi with the 
number of the joints varying in the males; always five-jointed in 
the females. Labial palpi three-jointed. Prothorax very short, 
forming a collar. Wings four, membranous, deflexed in repose, 
more or less pilose, with few transverse veins. Legs long; 
cox elongated; tibiz usually furnished with long spurs; tarsi 
five-jointed. 
Eggs enclosed in a jelly-like substance. 
Larve generally aquatic* and furnished with external respiratory 
filaments. Legs six, and two anal crotchets; the first abdominal 
segment with lateral and median processes. Residing in cases 
which are either free or fixed. 
Pupz remaining in the cases until shortly before the metamor- 
phosis. Antenne and legs free. Mandibles strong and often 
dentate; only used for the purpose of breaking through the case. 
It is not my intention to enter into a lengthened examination 
of the reasons that have induced Entomologists to consider these 
insects either as forming a distinct Order, or as a part of the 
Neuroptera. Among modern authors, on the one hand rank the 
names of Kirby, Leach, Curtis, Stephens, Westwood and Kolenati ; 
on the other, Pictet, Rambur, Brauer, Hagen, &c. It is with no 
disrespect to the opinions of the latter gentlemen that I elect to 
follow the example of most of my countrymen, and to consider 
the Trichoptera as forming a distinct Order. It appears to me 
that amongst the Newroptera (in the Linnean sense) are included 
two or three Orders, each of co-ordinate value with those that 
have been universally received as such, and which cannot be re- 
tained in such close relationship without outraging the laws of 
classification both metamorphotic and cibarian, 
If the claims of the Trichoptera to be considered a separate 
Order be admitted, the families still remaining in the Neuroptera 
will be scarcely less discordant than before, and it follows that the 
* The only well-authenticated exception is Enoicyla pusilla, Burm., which 
is not a British species. 
