BOTH THE SEXES IN DIPTERA. 367 



SimnlUcl(P. — In Slinulium oniatum, Meig., the forcipes superiores are small and hairy ; 

 the forcipes iuferiores large, and each have a small spine placed symmetrically opposite 

 each other near the ends. On the theca appear to be barbed appendages, but my 

 preparation is not satisfactory, and I cannot trace the apodeme. In ^S*. reptans (Linn.) (?) 

 I can make ont an arrangement of the theca with some aflB.nity to that found in the 

 Culicidae ; there is, however, a central apodeme which is forked at its junction with the 

 theca. The females have the usual valves, a single receptaculum, and a pecnliarity in 

 the shape of a bifurcate apodeme to the aperture of the vagina. This appears to answer 

 to the double apodeme or to the fused rods in the ovipositor of Ilusca domestica. 



Chironomidce . — The Chironomidse are a large group, but, like the Cecidomyiidse, of 

 fragile structure. I can trace all the valves and appendages in my preparations, but 

 not beyond that, the apodemes and ductus ejaculatorius eluding me. In the females 

 I cannot see the receptacula, these also not being of robust structure, except in 

 a single preparation of Ceratopogon obscurus, Winn., where I find three, and those 

 three relatively very large. I hope at some future time to make a special study of 

 these insects. 



OrphneijldlidcB. — The Orphnephilidse have only two European species, neither of 

 which is in my collection. 



JPsychodidcE. — The Psychodidae are minute and difficult of preparation. The females 

 of some species have egg-guides somewhat similar to those on Ptijchoptera alhimaiia and 

 Trichocera hiemalls. A male has four relatively very large forcipes, and I think I can 

 trace the apodeme. 



Leptidce and Therevidie.— The Leptidce and Therevidae are small groups of the 

 Tabanid type at which I have hitherto had very little opportunity of working. 



SceiwpinidcB and Cyrtida;. — The Scenopinida? and Cyrtidre are even smaller, both 

 families only numbering live species in the British list. Dufour has some remarks on 

 Scenoplnus fenest rails in his paper already quoted. 



Lonchopteridoi. — The genitalia of the Lonchopteridae, like the venation of the wing, 

 approximate to those of the Muscidae ; but the receptacula must be of a different 

 structure, as they do not show in the preparations cleared in potash, whereas they show 

 admirably in those of the Muscicke treated in this manner. 



Flati)pezidce.—1 have not had an opportunity of examining any species of the small 

 group of the Platypezida^. 



Pipunculidce. — In the Pipuuculidse the males have generally a very prominent hypo- 

 pygium, with an armature something between that of the Empidae and the Syrphidse. 

 In Chalurus spurius. Fall., the flagellum is furcate a short distance from the point ; the 

 theca also is furcate, and the flagellum enters it at this point. The rest of the theca 

 is mucli like that in the Empida), but at the interior end, though it widens out, it does 

 not form a sac, nor is it articulated with the cjaculatory apodeme. Instead of this, 

 a hyaline membrane proceeds from it with the usual small apodeme, as it is found in the 

 Muscidae (PI. 30. fig. 117). 



Conopidce. — In the Conopidse the male has often a bulbous hypopygium, but the 

 forcipes arc not of very definite shape, more valvular than hamate, but covered with 



