Diptera: Nemocera vera, N. anomala and J^remochaeta. 433 



(allied to Platyura) as figured by Westwood in the Trans. Entom. 

 Soc. V, p. 231, Tab, 23, f. 3, the ej'es form a broad contact below 

 the antennae; a New-Zealand species of the same genus has the same 

 conformation. 



The Psycliodidae show lunate eyes in several genera (Psychoda^ 

 Pericoma). i) 



The eyes of the Nemocera vera (in life) are generally dark,2) 

 Variations occur, even in the same genus. Cideoc sometimes has 

 bright-green eyes (pipiens)^ sometimes deep-black ones (ornatus): 

 in the genus Tipida, the same colours occur. Ctenophora pectini- 

 cornis has deep-black eyes; the Mycetopliilidae dark ones. I do 

 not remember seeing red or reddish eyes among the Nemocera 

 vera, except in Tipida nigra cf Q , the eyes of which are bright 

 purplish on the upper half and golden-yellow {cf) or reddish below. 

 Among the Nemocera anomala which I observed alive [Simtdiiim, 

 Blepharoceridae) the eyes are reddish aad purplish. Among the 

 Orthorrhapha Brachycera the eyes of the Asilidae and Dolicho- 

 podidae are generally greenish, those of the JFJmpidae red, except 

 those of the Tachydromiae, which are olive-green. Among the Cy- 

 clorrhapha the red color largely prevails. 



Finely pubescent eyes occur in the Mycetophilidae and in some 

 Tipididae (the section Amalopina, also in Trichocera). In this 

 case the pubescence may serve as a protection against moisture, and 

 not against an excess of sun-light, which seems to be its destination 

 in some other families {Syrphidae). It is remarkable at the same 

 time that some genera, the imagos of whicli live near, or almost in 



i) I have for a long time beeii puzziing about the position of the 

 Psychodidae in the System. Latreille connected them with the Ceci- 

 domyidae. In the introdnction to my monograph of the Tipulidae 

 (Monogr. N. A. Dipt. 1868, Vol. IV, p. 3) I said: „the connection bet- 

 ween ihe Psycliodidae and the E^nopterina is of a very obscure kind, 

 and unless fuither developed by Observation cannot have any scientific 

 value". But why should not the Psycliodac stand in a closer rela- 

 tionship to the Ckdiciclae? Both have lunate eyes, a certain resem- 

 blauce in the venation of the wings, an ambient vein, the veins clothed 

 with hairs or scales; Phlebotomus draws blood like a Oidex; finally, 

 according to the anatoniists, Cidex and Psychoda (in the imago-state) 

 have five Malpighian vessels, instead of four, the ordinary number 

 among Diptera. Tlie larvae may be difFerent, but the larvae in the 

 three families : Oidicidae, Chironomidae and Psycliodidae are inex- 

 haustible in their capabililies of adaptation. 



2) Dark eyes are not necessarily connected with crepuscular habits. 

 Sun-loving species of Anthrax and Syrphidae have often nearly 

 black eyes. 



XXXVU. Heft lY. 28 ' 



