Bibliographical Notices. 433 



working in the most painstaking and earnest manner upon this 

 difficult group of insects ; and Mr. M'Lachlan's papers relating to it, 

 which have appeared from time to time in the puhlications of the 

 Linncan and Entomological Societies, and in other periodicals both 

 in this country and abroad, have furnished sufficient evidence of his 

 determination to arrive, if possible, at trustworthy results in the 

 discrimination and classification of the group. His most important 

 contribution to Trichopterology (if we may use such a term) is un- 

 doubtedly his monograph of the British species of the group, pub- 

 lished in 1865 in the Transactions of the Entomological Society. 

 Of this he says, in the introduction to the work of which the title 

 stands at the head of this notice, that " the experience of nearly ten 

 years appears to show that this work has been of some service to 

 European entomologists generally ;" and, indeed, considering the 

 conscientious care with which it had evidently been prepared, we 

 can easily believe that this modest claim to merit is more than 

 justified. Nevertheless the author confesses " to having for a long 

 time been dissatisfied with it. There are many points of detail," he 

 says, " concerning which time has proved my earlier views to have 

 been erroneous, or at any rate badly expounded ; and the figures — 

 however gratifying to me they may have been in 1865 — were ill- 

 drawn, and their original defects magnified by bad engraving." How 

 far we are bound to accept Mr. M'Lachlan's estimate of the value 

 of his own work may be a question ; but there can be no doubt that 

 entomologists have every reason to be thankful that he has formed 

 it, seeing that his doing so has led to his undertaking the labour of 

 preparing the monographic revision of the Trichoptera of the Euro- 

 pean faunal region, the first three parts of which are now before us. 

 His object in this work is to describe, figure, and classify all the 

 Trichoptera inhabiting Europe, Northern Asia, and the Mediter- 

 ranean district, the materials for which now existing in collections 

 he estimates will represent from 250 to 300 species, although he 

 anticipates that new forms will probably be brought under his notice 

 during the progress of the work. But the amount of labour involved 

 in the revision of these species cannot well be estimated from the 

 smallncss of their number ; the minuteness of the characters distin- 

 guishing the genera and species (which are in many cases derived 

 more or less exclusively from the peculiarities of the anal append- 

 ages) necessitates an enormous amount of careful examination, 

 whilst the neglect or misinterpretation of these characters by the 

 earlier describcrs adds immensely to the labour of determining the 

 species noticed by them ; and the further fact that many of the 

 descriptions of species were written by entomologists who had made 

 no special study of these insects adds greatly to the difficulties of 

 nomenclature. In fact, considering how little the study of the 

 Trichoptera has been in fashion among entomologists, the number of 

 synonyms pertaining to many of the species is really wonderful. 



From its nature Mr. M'Lachlan's work is scarcely open to criticism, 

 except upon points of detail, into which no one who has not made 



