4 BULLETIlSr 116, UNITED STATES NATIONAL MUSEUM. 



them in Germany. The species is common also in tbe United States. 

 I translate as follows: 



rhe male of the fly possesses on the first tarsal joint a beautiful, regular fringe [the 

 fringe is on middle tibia and tarsus, our fig. 128a — ^J. M. A.], the purpose of which is 

 not immediately perceptible. * * * I have now observed the pairing of these 

 insects, and am convinced that the structure serves as arC actual ornament to the 

 male. * * * The male came flying up, and hovered for a time so close over the 

 quietly resting female that the fringed tarsi hung down immediately before her eyes. 



I can add similar observations on two more species, not hitherto 

 published. 



Dolicho])us aldricJiii Wheeler is a species quite common on wet 

 earth at edge of water at Moscow, Idaho. The male has plain front 

 tarsi, but the middle ones (fig. 182a) are elongated and thickened 

 and very black. The male takes up a position on the earth in front 

 of the female and facing her, an inch or so away. He then vibrates 

 his wings, holding them at right angles to the body, and at the same 

 time elevates the long middle legs, holding them also horizontally at 

 right angles to the body, and describes a small circle with them, both 

 together, very like the setting up drill of military cadets. 



DolicJiopus longimanus Loew is a species with much elongated front 

 tarsi (fig. 138a, last four joints), the last joint being black and en- 

 larged. I observed the courtship on the trimks of trees at Simpson 

 Park, Big Stone City, South Dakota, in 1896, and although I have 

 no notes I believe I can record the facts even yet. The male ap- 

 proaches the female directly from behind (below, as on vertical sur- 

 faces they always face upward) ; he walks on the tips of his toes with 

 his front feet, assuming in consequence a reared-up attitude. As he 

 comes to the female he advances his front tarsi on each side of her 

 until their tips are even with her head, which is about as far as they 

 can be extended. Then he deliberately raises the tarsi until the 

 enlarged apical joint touches on each side the eye of the female, con- 

 tinuing the movement upward. But just as his tarsi touch her 

 eyes, he advances his hypopygium and attempts to grasp the tip of 

 her abdomen. She immediately dodges away, and the performance 

 is repeated. 



In the five species reported, it will be noted that the movements 

 are quite different for each. There is no doubt whatever that many 

 other species can very easily be observed in their characteristic 

 behavior. 



The larval habits arc very slightly known for the entire family, 

 and especially for this genus, a surprising fact when the abundance 

 of adults is considered. Hart ^ describes three undetermined larvae, 

 which Malloch,^ refers to DolicJiopus, giving a figure of one of them.* 

 One was taken boring in decaying and watersoaked stems of rushes, 



2 Bull. 111. state Lab. X. 11., vol. 4, 1895, p. 268. 3 idem., vol. 12, 1917, p. 406. * PI. o7, fig. 3. 



