538 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



reworking of type material, have cleared up nuicli of the confusion that has at- 

 tended the taxonomy of both Neuroptera and Mecoptera in North America and 

 Europe, but continuation of sucli investigations is still the prime need. Basic 

 and extensive study collections of Neuroptera and Mecoptera are contained in 

 the British jMuseum (Natural History), which includes the Walker and Mac- 

 Lachlan collections (among others), and in the Museiun of Comparative Zoology, 

 Harvard University, which contains the Hagen and Banks material. Other large 

 museums, of course, also have important study collections, but of more recent 

 origin. 



Another need, just as important, is studies on the life histories and im- 

 mature stages of these two orders of insects. Virtually only the British and cer- 

 tain European species are satisfactorily known. 



TRICHOPTERA 



Herbert H. Ross 



Illinois Natural History Survey, XJrhana 



If the starting point of this discussion had been set two years earlier, it could 

 honestly have been said that caddis flies in North America were then represented 

 by only a handful of scattered descriptions. But in 1852^ F. M. Walker de- 

 scribed about 60 species from North America, and this was followed in rapid 

 succession by additional descriptive efforts by Hermann Hagen, Kolenati, and 

 the Abbe Provancher, so that by 1880 some 150 species were described from the 

 North American region. 



Even with the inclusion of Walker's work there was relatively little known 

 about North American Trichoptera in 1852. Only a few species described by 

 Thomas Say had been illustrated in American scientific literature, while the 

 other species were known only by brief, inadequate descriptions. The European 

 fauna, however, was surprisingly well investigated. Especially notable had been 

 the researches and publications of the Swiss worker, Pictet. In 1834 he gave a 

 fine account of the main groups of the European Trichoptera, illustrating not 

 only many pertinent features of the adults and larvae, but also life-history data 

 on most of the large groups. Pictet divided the Trichoptera into about ten 

 genera, and these anticipated in almost uncanny fashion the major groupings 

 which later became established in the order. Contemporaneously with Pictet, 

 two British workers, Curtis and Stephens, made significant contributions to the 

 recognition of caddis-fly genera, and Zetterstedt added considerably to the 

 knowledge of the fauna of northern Europe. Up to this time, however, the 

 generic and specific diagnoses were on a very superficial level, and information 

 was available in usable form for only a few sections of the European fauna. 



1. Here and elsewhere in this article, dates refer only to publications, for which the 

 full references may be found either in Bull. 292, New York State Museum, or in Zoological 

 Record. 



