110 Mr. F. W. Edwards on the 



Ilifpopharyiur (fig. 1, p. 109). — Frey has found tliat in most 

 MyCETOPHILID.E, as also in ScIAHID.E and CECIDOMYIIDJi, 

 the hypoi)liarynx is but poorly deveUiped, and is fused on to 

 the upj)in" surfiice of the lahium. The only exception he 

 noted was in the genus Bnlitophila, in which the hypo- 

 pharynx is free at the tip; he hail not, however, examined a 

 large number of forms, and Mi/cetohia was not among them — 

 it has the hypopharynx very well developed and entirely free 

 from the labium, being connected rather with the labrum. 

 niii/phus and Olbiogaftter likewise have a free hypopharynx, 

 though its form is very diverse in the three genera. In 

 Mycetohia it is trilobed at the tip, the middle lobe having a 

 finely toothed margin ; in Olhiogaster it is simple, and also 

 in Rhyphus, though in the last-navned genus it is straighter 

 and more pointed. It is connected with the " pharyngeal 

 pump," which seems to be rather better developed in Myce- 

 tohia than in other Mycetophilid^, and is even more 

 conspicuous in the RiiYPHiDJi. 



Maa-Uhe (fig. 2). — In both families the parts of the maxillas 

 present are stipes, galea, and palpus. The stipites are appa- 

 rently absent in Ditomyia (fig. 4 a) and perhaps in Macro- 

 cera ; small in Platyura (fig. 4 h) ; well developed in the 

 other genera, attaining their greatest size in the more typical 

 Mycetophilidj^, such as Phronia (see fig. 4 d), Exechia, 

 and Mycetophila. In these last-mentioned forms the galea or 

 blade of the maxilla is very much reduced, but in the more 

 primitive MYCETOPHILID.E and in the Ehyphid^ it is quite 

 large. 



The maxillary palpi of Rhyphun are four-jointed (without 

 reckoning the small basal palpiger, which may be a true 

 joint). The second joint is somewhat enlarged, and contains 

 a peculiar gland provided with a duct which opens by a pore 

 at the tip of the joint. Olhiogaster has similar palpi, but 

 the joints differ in their relative lengths, and the duct of the 

 gland in the second joint is shorter ; the palpiger has more 

 the ajipearance of a true joint. In Mycetohia the palpi are 

 only three-jointed, but, as the basal joint contains a gland 

 very similar to that of li/iyjjJois, it is probabl}^ safe to assume 

 that the palpi have become three-jointed by the fusion of the 

 first two. In both genera the penultimate joint is roundish, 

 the terminal one more elongate. Many Mycetophilid^ 

 possess a structure in the second palpal joint which is, 

 perhaps, comparable with the gland above referred to; but 

 in no other case that I have observed is this gland provided 

 with a duct, nor does it (except in the case of Simulium, 



