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XXII. Characters of New Species of £Jxo/zc Trichoptera ; 

 also of one Neio Species inhabiting Britain. By 

 R. M'Lachlan, Esq., F.L.S. 



[Read 6th January, 1862.] 



The exotic species here described are for the most part contained 

 in the national collection, and are natives of China, Australia and 

 New Zealand. 



It has been found necessary to construct several new genera for 

 the reception of species, which, even with the most liberal ideas as 

 to the elasticity of generic characters, will not fit satisfactorily into 

 any already existing genus. This is but an effect of the meagre 

 knowledge we possess of insects of tliis order from distant quar- 

 ters. When the wide diversity from European forms exhibited in 

 exotic insects of other orders is taken into consideration, it is not 

 surprising that these should present equal differences, almost un- 

 known as they at present are. 



With respect to the geographical distribution of Trichopteroiis 

 families, one very remarkable fact strikes the observer, viz. that, 

 apparently no species belonging to the two great families Phryga- 

 tudce and Linmephilidce are found south of the equator ; certainly 

 none have yet been described. These appear to have their 

 metropolis in the cold and temperate regions of the northern 

 hemisphere, and decline in numbers as we proceed south, till in 

 the tropics they are very few, and at the equator seem to disappear 

 entirely. That some may yet be discovered is of course possible, 

 but taking into consideration that they are usually insects of large 

 size, likely to attract attention, 1 think it certain that if they be 

 not altogether wanting, they must be very scarce. 



Fully as many more undescribed exotic species from the old 

 world are contained in the national collection, and a considerable 

 number from North and South America, but as a synopsis of the 

 American Neuroptera (including the Trlchopttera) by Dr. Hagen 

 is on the eve of publication by the Smithsonian Institution,* the 

 determination or description of these latter must be deferred till 

 its appearance. 



* This Work has since been published, and contains descriptions of 150 species 

 of North American Trichoptem, and a catalogue of 23 species from South 

 America. • ' - ' 



