Diptera: Nemocera vera, N.anomala and Eremochaeta. 441 



parts etc. Boston, 1881, pp. 14, 15, 20). Dimmock tried experiments 

 with the male Culex (1. c. p. 22) witbout success; he thinks that, on 

 anatomical grounds, they caniiot obtain food by piercing the skins 

 of aninials. Among the older authors J. H. Jördens (Entom. and 

 Helminthol. d, menschl. Körpers, 1801, Vol. I, p. 165; quoted by 

 Dimmock, 1, c. p. 50) affirmed that male mosquitoes can bite; and 

 more recently E. Ficalbi (Bullet. Soc. Ent. Ital. 1889, p. 25) asserted 

 positively that he had observed two italian species in which both sexes 

 siick blood. He is probably right in asserting at the same time that 

 originally all the species of Culex are suckers of vegetable matters 

 („tutte le zanzare filogeneticamente dovevano esse fitofaghe"). I am 

 not aware of the existence of any bloodsuckers among the Tipulidae, 

 Cecidomyidae and Mycetophilidae. Some genera of these three fa- 

 milies sometimes show a remarkable development in length of their 

 rostrum and mouthparts, probably intended for sucking moisture, or 

 the sap of flowers. Such genera are Geranomyia, Elephantotnyia 

 and Toxorrhina (Tipulidae), O/inorrAywc/ia (Cecidomyidae), Gnoriste, 

 Asyndidum, and the australian genera Lygistorrhina and Antria- 

 dopMla (Mycetophilidae). (Compare the Additions.) 



In their general aspect (as I have already stated on p. 424) the 

 Nemocera vera are distinguished by slenderness and lightness; the 

 elongation of the abdomen in comparison to the thorax is especially 

 noticeable. The habits of the Nemocera vera are rather crepuscular 

 (and also matutinal) ; they prefer shady places and cool evening hours. 

 The crepuscular and nocturnal habits of the Culicidae and Cerato- 

 pogons (in comparison with the sun-loving Diptera, like the Taha- 

 nidae, Bombylidae, Syrphidae) are well-known; also the shady 

 abodes of the Mycetophilidae and Psychodidae, the evening dances 

 of the Chironomidae and certain Tipulidae (Trichocera, Limnohia 

 Chorea^ Erioptera imbutctj, the dances in dark recesses of Dolicho- 

 peza. These evening-dancers form a contrast with the swarms of 

 Simididae (Nem. anomala) that disport themselves in the brightest 

 sunshine; the difference is probably conditioned by the stouter inte- 

 guments of the latter, which enable them better to resist dessication. 

 The Nemocera vera dance, but never hover; hovering, as I have 

 shown elsewhere (Chaetotaxy, Trans. Ent. Soc. London, 1884, p. 501) 

 is connected with holopticism. 



It remains for me to say a few words about Dixa. This genus 

 may by well placed among the Nemocera vera on account of its re- 

 mote eyes in both sexes, the absence of pulvilli, and its general ap- 

 pearance, but it cannot bc fitted into any of the established families. 

 The Tipididae seem to be the ncarcst to Dixa^ but the latter ditfers 



