INTRODUCTION. 39 



guttata Macq.) and E. aprilina 0. S., Idioplera pulchella Meig. 

 and 7". fasciolata 0. S. ; Amalopis tipulina Egger and A. incon- 

 stans O. S. ; Cylindrotoma distinctissima M. and G americana 

 O. S. Judging from the description of Limnobia varinervis 

 Zett., which is an Amalopis, it must be very like A. hyperborea 

 O. S. 



Closely resembling, but certainly different species are Pedicia 

 rivosa L. and P. albivitta Walk., Rhipidia uniseriata Schin. 

 and R. f delis 0. S., Limnobia annulus Lin. and L. cinctipes 

 Say, etc. 



An undescribed European Via is very like XI. elegans 0. S. 

 The European and North American species of Trichocera are 

 closely alike in appearance,* but require comparison. 



The comparison of the large genera gives occasion to the 

 following remarks : — 



In the genera Limnobia and Limnopliila the species with 

 handsomely pictured wings seem to be more abundant in Europe. 

 The species Limnobia flaeipes Meig., sylcicola Schum., nube- 

 culosa M., nigropunctata Schum., and similar ones, have no 

 corresponding representatives in North America. The same 

 remark applies to the subgenus Pcecilostola Schiner (Limno- 

 phila), represented by four species in Germany, and not dis- 

 covered yet in North America. 



In the genus Erioptera I am not aware of the occurrence in 

 Europe of the subgenera Mesocyphona 0. S. and Acyphona 0. S.; 

 however the European Erioptera are very imperfectly classified. 



If my limited knowledge prevents me from pushing very far 

 the comparison of the North American with the European fauna, 

 I have still less means for a comparison with the faunas of the 

 other parts of the world. Almost nothing is known about them ; 

 the scanty facts in our possession will be mentioned, however, in 

 the respective sections and genera. 



8. On the species of No?ih American Tipulid.e breVipalpi (in- 

 cluding the Cylindrotomina and P ty diopter ina), described in 

 former publications. 



Forty-four Tipulidse coming within the scope of the present 

 volume have been enumerated in my Catalogue of the Described 

 Diptera of North America, Washington, 1858. Omitting two 

 collection-names of Mr. Harris, which had never been published 



