6 Orthorrhapha biachycera. 



of the three genera mentioned it has been observed, that the males 

 catch a prey, kill it but do not devour it ; on the contrary they carry 

 it with them and meeting a female this gets the prey while the copu- 

 lation takes place. During the copulation the female sucks the prey, 

 but when the copulation is fmished, the female drops the prey. Whether 

 the prey is a means for attracting the females or the animal juices 

 are perhaps of importance for the fecundation , and whether the females 

 also feed in other ways are questions to be solved in the future. 

 Several species of Hilara envelop the prey in a web before presenting 

 it to the female. An American species of Empis makes a curious frothy 

 balloon at the mating time. For particulars about these phenomena 

 see under the three genera mentioned. 



From the palæarctic region about 675 species of Empids are 

 known, and from North America about 440; eleven are recorded to 

 be common to both regions. 



I am aquainted with no case of Hymenoptera parasitic on Empids 

 and I have found none recorded in the literature, 



Empididae earlier recorded from Denmark. — Kramer (Specim. 

 Insectol. Dan. 1760) has one species, Empis borealis. Briinniche (Prodr. 

 Insectol. Siælland. 1761) mentions the same, and in 1763 (Pontoppi- 

 dan, Dansk. Atl. I) he again mentions only the same. What this species 

 may be cannot be said, perhaps the common Empis tesselata. O. F. 

 Muller (Faun. Fridrichsd. 1764) mentions two species, E. livida and 

 flava, the latter new. The first is perhaps correct, the latter may be 

 one of the species of Xanthempis, perhaps stercorea. — Fabricius has 

 in 1787 (Mantiss. Insect.) one species, Empis minuta. hi 1794 (Entom. 

 Syst. IV) he enumerates seven, Empis davipes, nigripes, fuscipes, mi- 

 nuta, flavipes, nigripennis and melanocephala, and in 1805 (Syst. Antl.) 

 he enumerates one more, E. lineata, and the species fiavipes, fuscipes, 

 nigripennis and melanocephala he has now under Tachydromia. He 

 has thus eight species for which Denmark is given as locality. The 

 species are all described as new. E. clavipes is Hyhos grossipes L. 

 and E. lineata is E. livida L. With regard to the other six I may 

 give somo explanation. For all six species Fabricius quotes the col- 

 lections of Tonder-Lund and Sehestedt. In this collection they are 

 also found, and the examination of the species gave the following 

 results: Empis nigripes: two specimens present, that on the label is 

 Bhamphomyia dissimilis, the other is Empis vernalis; Empis minuta: 

 the specimen on the label is a Pliora, the other a Sciara; Tachydromia 

 fiavipes; the specimen on the label has lost the head, but may be 

 this species, the other is T. pallidiventris; Tachydromia fuscipes: the 

 specimen on the label is Hilara carinthiaca, the other is an undetermin- 



