DOLICHOPODID.E. 229 



on the proboscis in most species. Antennae three-jointed, 

 inserted more or less above the middle of the eyes, close 

 together, the first two joints always short: third joint 

 commonly oval, but in several genera lengthened, some- 

 times more so in the male; arista dorsal, subapical, or 

 completely apical. Thorax in some genera with a well- 

 marked flat or concave area in front of the scutellum on 

 the dorsum. Abdomen conical or a little compressed, 

 in Hydrophones and Scellus sometimes peculiarly small 

 and retracted; hypogygium varying much in form in 

 different species, generally rather conspicuous. Coxae 

 generally short, legs in most genera of moderate length, 

 in some elongate, those of the males frequently developed 

 into some ornamental structure; the front femora are 

 thickened in a few genera. Wings generally hyaline, yet 

 often with dark markings, which may take the form of a 

 definite pattern, or may follow the veins indistinctly, or 

 may be evenly diffused. Anal cell always very short; 

 two or three posterior cells; sixth vein always very short, 

 sometimes absent. 



This family perhaps surpasses any other natural group 

 of animals in the variety of secondary sexual characters 

 possessed by the males. These are ornaments, and are 

 paraded before the females, as are similar ornaments in 

 the peacock and turkey-cock. They may occur in the 

 tarsi, tibiae, femora, wing-apex, face, third joint of an- 

 tenna, arista, palpi, and still other places. Contrary to 

 the usual theory, these characters seem very constant, 

 and are the main reliance in distinguishing the species. 

 Identification in the family is rendered delightfully easy 

 in the majority of cases, if one has the male. 



The larvae are almost wholly unknown in the United 

 States; several species have been worked out in Europe. 

 They are found in moist earth rich in decaying vegeta- 

 tion, upon which they feed: Dr. A. D. Hopkins has 



