Helophilus, 447 



various Gompositæ; some are generally seen on water-plants ; some- 

 times they are seen flying low over the water in ditches. The genus 

 goes far towards the north, two species being inhabitants of Green- 

 land. Verrall gives (Brit. Fl. VIII, 547) an observation of the coart- 

 ship in H.Uueattis; the female rests sitting but vi^ith the wings shghtly 

 vibrating, while the male hovers above it with its head bent wonder- 

 fuUy downwards and its wings very rapidly vibrating, at the same 

 time the whole body shakes "like a dog just out of the water"; I 

 have myself observed the same in this species ; this behaviour remem- 

 bers of the courtship in Dolichopodids. Verrall asks whether any 

 stridulation can go on in which the peculiar scabrous patch at the 

 base of the femora or the ribbed anal vein take a part. 



About 20 species of the genus are known from the palæarctic 

 region; 11 have been found in Denmark. 



As the species are to some degree diverging several subgenera 

 have been established, but have given rise to different opinions; 

 Rondani in 1875 separated Liops off for the species vittatus (then 

 placed under Mallota) on account of its peculiar antennæ, and 

 Mesembrius for peregrinus (not Danish) on account of the approximated 

 eyes in the male and the dilated tarsi; in 1883 Bigot established 

 Eurinomyia {Eurimyia) on H. lineatus, which he very curiously took 

 for a new species and narned rhingioides. Girschner (111. Wochenschr. 

 f. Entom. 1897, 603) divides the genus into two divisions after the 

 squamulæ; the large species have the thoracai squamula somewhat 

 haired on the upper surface, and they have no distinct stigmatical 

 cross-vein; here he has Helophilus s. str. and Mesembrius; the smaller 

 species have the squamula bare above and a stigmatical cross-vein; 

 under this second division he has the subgenera Liops, Parhelophilus 

 with frutetorum, versicolor and lunulatus, and Eurinomyia with lineatus 

 and transfugus; Parhelophilus includes thus the species of the second 

 division not belonging to Liops or Eurinomyia, but he gave otherwise 

 no characters for this new subgenus. Verrall is of opinion that the 

 squamulæ in frutetormn and versicolor are hairy above as in the large 

 species, and he reiecis]Parhelophilus, placing its species except lunulatus 

 to Helophilus. Becker (Berl. ent. Zeitschr. LV, 1910, 219) has studied 

 the question anew, and he declares Girschner to be right; I have 

 also studied the squamulæ, and I can confirm Becker's statement. 

 On the other band Verrall is right when he separates lunulatus and 

 piaces it to Eurinomyia. Becker also rejects Parhelophilus, but according 

 to the squamulæ he naturally piaces its species in Eurino?nyia. Now 

 it cannot be denied that the species frutetorum, versicolor and con- 

 similis are closely allied to each other and less closely to the other 



