434. BibMogrcqphtical Notices, 



the Trichoptera his special study can enter without presumption. 

 The author describes the general structure of the Trichoptera, and 

 characterizes the families, genera, and species constituting the group, 

 tabulating them in each case in order to facilitate the task of dis- 

 crimination. The synonymy of the species is given in full ; and wo 

 would suggest that the synonymy of the genera should also be given, 

 as at present many contractions of generic names appear in the 

 specific synonymy, the meaning of which the student cannot ascer- 

 tain without referring to other works. 



With regard to the position of the Trichoptera in the system, Mr. 

 M'Lachlan is not inclined to adopt either of the two plans of dealing 

 with the Linnean JNTeuroptera advocated by different schools of 

 entomologists. He would neither retain the old order in its inte- 

 grity, nor, removing the groups with imperfect metamorphosis to 

 the Orthoptera, restrict the term Ncuroptera to the Planipennia and 

 Trichoptera, which he thinks " do not show sufficient connexion to 

 warrant their being considered co-ordinate." His own inclination 

 would be to split up the JSeuroptera of the older entomologists into 

 several orders, of which, under such treatment, the Trichoptera 

 would undoubtedly be one ; and in his present, as in former works, 

 he treats them as constituting an order. 



As to the question of the relationship of the Trichoptera to the 

 Lepidoptera, there is, of course, room for considerable difference of 

 opinion. Mr. M'Lachlan strongly maintains that there is such a 

 relationship, and that it " bears the impress of actual homology 

 rather than of casual analogy." In this view, notwithstanding the 

 objections that may be urged against it, we are inclined to think he 

 is in the right ; the perfectly phalamoid facies of so many of the 

 smaller Trichoptera, the clothing of the wings, the state of the 

 buccal organs, the form and structure of the larvae, and even their 

 habits, all seem to point towards a direct alliance with some of the 

 Micro-lcpidoptera or with the Psychidse. 



The figures which illustrate this work, and show in outline the 

 venation of the wings and the characters of the anal appendages and 

 other organs upon which Mr. M'Lachlan depends for the discrimi- 

 nation of the genera and species, are all drawn by himself under the 

 microscope, and certainly show a great advance, both in execution 

 and in fulness of detail, upon those accompanying his Monograph of 

 the British Caddis Flies. The details of each species arc represented ; 

 and, so far as we are acqua : nted with the objects, the figures leave 

 nothing to be desired. 



In concluding this notice we can only express a hope that ento- 

 mologists will regard it as a duty to subscribe to a work which is in 

 every way one of the most creditable that has appeared in Britain 

 for a long time, and thus, as far as possible, prevent what is un- 

 doubtedly a labour of love on the part of the author from being at 

 the same time a heavy loss to him. 



