114 KANSAS UNIVERSITY QUARTERLY. 



NEMISTRINID^. 



1 have examined the mouth-parts in but two genera of this family. 

 The structure, except the galea, is so nearly identical in these, how- 

 ever, that I believe it to be the family type. The paraglossae and 

 ligula present only minor differences from those parts in Apiocera and 

 Rhaphiomidas . Neither organ forms a complete tube. The para- 

 glossae have a more thin, pointed extremity than in the other men- 

 tioned species, and the ligula is more rounded at the extremity. The 

 palpifers are extremely slender, especially in the long-proboscid form. 

 They are cylindrical, firm, without expansion distally, and bare. The 

 palpi seem merely appendages of the palpifers. They arise at a con- 

 siderable angle from the flattened, slightly expanded base, and, though 

 apparently two-jointed, are long and whiplash-like. The galea is 

 fully open on the upper side in the broadly labiate species, more 

 closed, and more slender and firm in the long-proboscid species. The 

 suctorial flaps in Hlrmoneura are very large, with numerous curved 

 ridges, and small, irregularly distributed, round, translucent spots. 

 The outer side is covered with short hairs. The labella differ from 

 those of Apiocera in the greater number and smaller size of the pseudo- 

 tracheal ridges, and in their relatively larger size. In Megistorliynchus, 

 the labella are terminal, long, narrow and divaricable — very much 

 like the same organs in Rhaphiomidas. 



THEREVID^. 



In Thereva and Psilocephala, the forms examined, the structure is 

 essentially the same as in those already described. The paraglossae 

 are longer than the ligula, both of which organs are deeply channeled, 

 forming, in apposition, a closed canal. The palpi are one-jointed, 

 elongate, irregular in outline, and very hairy. The palpifers are very 

 slender, straight, and firm, arising from the base of the palpal projec- 

 tion. They are considerably shorter than the sucking parts above, 

 and not as long as the palpi. In Thereva, the paraglossae and ligula 

 are more elongate and slender than in Psilocephala. The galea is- 

 open above, and terminates in the large labella, which are provided 

 with irregular ridges, as in Apiocera. 



ASILIDjE. 



A uniform structure seems to prevail throughout the Asilidae, but 

 with minor differences characteristic of species, genera and, appar- 

 ently, subfamilies. I have been able to examine only a comparatively 

 small number of the genera, but I feel sure that conclusions drawn 

 from these will be applicable to the whole family. In Mallophora, 

 Promachus, Proctacanthus, and Asilus, the palpi are large and but 

 one-jointed. In Stetiopogon, Scleropogon, Deromyia, Cyrtopogon, Ospri- 



