Introiluction. 3 



ledge of the Danish Diptera is based chiefly on liis colieclion, now in our 

 Museum ; he published in 1839 — 40 : Systematisk Fortegnelse over de 

 i Danmark hidtil fundne Diptera (Naturhist. Tidsskr. II, III). He only 

 reached through CuUcidæ, Tipididæ and Mycetopliilidæ, and he esta- 

 blished not so few new species. In the same periodical (IV, 1842) he 

 published: Danske Dolichopoder, and here also he described some new 

 species. His works to a high degree advanced the knowledge of the 

 groups treated. All species enumerated by him are included in Zetter- 

 stedt's work. 



Zetterstedt has, as is well known, in his great work: Diptera 

 Scandinaviæ, Vol. I— XIV, 1842—60, also recorded the Danish species 

 known at this time. He knew those species very well, as he had 

 received from Stæger I think almost all species tlien known to our 

 fauna, and he also included in his work the species mentioned by 

 Stæger in his papers. He enumerates in all 1439 Danish species of 

 which the last enumerated are found in Vol. XII, 1855, and this 

 nuniber thus represents the number of species then known. As will 

 be seen the knowledge of the fauna had made a considerable step 

 forwards since 1805, the year in which the last work of Fabricius was 

 published. 



We now have reached that point on which the knowledge of the 

 Danish fauna of Diptera stands for the present as far as this know- 

 ledge is found in the literature of the subject. Still there are several 

 papers on Danish flies or their larvæ, or in which Danish flies are 

 mentioned; thus a series of papers by Stæger mostly dealing with single 

 genera or species; these are all mentioned by Zetterstedt; moreover 

 papers of F. V. S. Jacobsen, Ghr. Drewsen, J. C. Schiodte. H. Low, 

 Fr. Meinert, H. Borries. J. E. V. Boas, R. C. Mortensen, E. Rostrup, 

 S. Rostrup and J. G. Nielsen, but these add no or at all events only 

 a few single species to our fauna. 



The material I have worked out for the present paper consists, 

 besides my own collection, of the coUection of Danish Diptera in our 

 museum. This collection is, as already mentioned, for the greatest 

 part collected by Stæger and chiefly or exclusively in the environs of 

 Copenhagen; to this however a small number of species are found in 

 it from different parts of our country collected by Schiodte, Drewsen, 

 Jacobsen, O. G. Jensen and a more important collection by H. J. Hansen. 

 Danish species are also found in Westermann's collection and in the 

 old collection of Tonder-Lund and Sehested, in which latter some 

 Fabrician types are found. Further the following gentlemen have given 

 me admission to their collections of Diptera: W. Schlick, G. Larsen, 



