504 



DIPTERA 



from all the other Diptera except from forms of Aschiza, and 

 from certain Authomyiidae, with both of which the Acalyptratae 

 are really intimately connected. Considerable difference of 

 opinion prevails as to the number of these divisions^ but the 

 families usually recognised are : — 



1. Doryceridae. 



2. Tetanoceridae. 

 ■i. Sciomyzidae. 



8. 



9. 



10. 



Diopsidae. 

 Celypliidae. 



fSepsidae 



\incl. Pioj)liilidae. 



fChloropidao 

 \( — Oscinidae). 

 Ulidiidae. 

 Piatystoinidae. 

 Ephydridae. 



11. Heli)iiiyzidae. 



12. Dryomyzidae. 



13. Borboridae. 

 Phycodromidae. 

 Tliyreophoridae. 



( Scatophagidae. 



y{ = Scatomyzidae). 



f Geomyzidae 

 \incl. Opomyzidao. 



(Drosophilidae ; 

 \incl. Asteidae. 

 Psilidae. 



fTaiiypezidae 



\^( — Micropezidae). 



14. 



15. 



16. 



17. 



18. 

 19. 

 20. 



21. Trypetidae. 



„,-, f Sapromyzidae 



\^incl. Louchaeidae. 



23. Rhopalomeridae. 



24. Ortalidae. 



r Agromyzidae 



25. -! incl. Phytomyzi- 

 \^ dae. 



26. Milichiidae. 



27. Octhipliilidae. 



28. Heteroneiiridae. 



29. Cordyluridae. 



Brauer associates Conopidae with Acalyptrate Muscids, and 

 calls the Group Holometopa ; applying the term Schizometopa 

 to the Calyptrate Muscidae. 



No generalisation can yet be made as to the larvae of these 

 divisions, neither can any characters be pointed out Ijy which 

 they can l)e distinguished from the larvae of the following 

 families. In their habits they have nothing specially distinctive, 

 and may be said to resemble the Authomyiidae, vegetable 

 matter being more used as food than animal ; many of them 

 mine in the leaves or stems of plants ; in the genus Dorycera the 

 larva is aquatic, mining in the lea^ves of water-plants, and in 

 Ephydridae several kinds of aquatic larvae are found, some of 

 which are said to resemble the rat-tailed larvae of Syrphidae ; 

 certain of these larvae occur in prodigious quantities in lakes, 

 and the Insects in some of their early stages serve the Mexicans 

 as food, the eggs being called Ahuatle, the larvae Pusci, the 

 pupae Koo-chah-bee. Some of the larvae of the Sciomyzidae are 

 also aquatic : that of Tetanocera ferruginea is said by Dufour to 

 consist only of eight segments, and to be metapneustic ; Brauer 

 considers the Acalyptrate larvae to be, however, in general, 

 amphipneustic, like those of Calyptratae. The Chloropidae are 

 a very important family owing to their occasional excessive 

 multijdicatioiij and to their living on cereals and other grasses, 

 various parts of which they attack, sometimes causing great losses 

 to the agriculturist. The species of the genus Chlorops are 



