348 EMPID^E. 



female, in which sex the last three abdominal segments are some- 

 times suddenly contracted, terminating in the usual pair of 

 stvliform lamellae. Legs comparatively slender, rather long, the 

 femora occasionally thickened, and more rarely the front or hind 

 metatarsi, or both pairs, more or less dilated ; tibiae sometimes 

 with apical spurs. The ornamentation of the legs variable, some 

 species having fan-like rows of scales or scale-like hairs on the 

 femora or tibiae, and sometimes on the metatarsi also ; bristles 

 and long hairs of specific value often present ; all the legs 

 ordinarily with short: pubescence. Wings : auxiliary vein not 

 reaching margin; 1st and 2nd longitudinal veins long, 3rd forked 

 towards tip ; upper branch of 4th vein forked at corner of disca! 

 cell ; lower branch of oth vein strongly recurrent, approximately 

 parallel with hind margin of wing, meeting anal vein at a widely 

 obtuse angle and making anterior margin of anal cell much longer 

 than posterior one ; anal cell much shorter than 2nd basal ; anal 

 vein attaining wing-margin ; discal cell present. Axillary lobe 

 of wing well developed; squamae small. The shade of the wing 

 is often darker in one sex in some males almost milky. 



Range. World-wide. 



Life-history. Little definitely known. The larvae live in moist 

 earth in woods, or less frequently in rotting tree-trunks. They 

 are amphipneustic, of twelve segments, and of the usual maggot 

 form. They are said to hibernate. 



The species of Empis are generally distributed, but prefer shaded 

 and somewhat moist situations. Many species occur at times in 

 vast numbers; some hover in the air. Presumably all are car- 

 nivorous, preying on soft Diptera and small moths. The mating 

 of some species takes place in the air, and affords a most interesting 

 study ; * others on the surface of water ; whilst in other species 

 the curious fact seems established that the male catches some prey 

 and presents it to the female, which devours it during copulation. 

 In one American species a small balloon of minute bubbles is 

 formed, in which a small dead fly, presumably prey, is enclosed, 

 <he balloon being discarded after copulation. 



Table of Species. 



1. Front tarsi in tf extraordinarily developed, as 



long as remainder of front legs ; $ un- [p. 349. 



known amplitarsis, sp. n., 



First tarsi in <3 not extraordinarily developed, 



nor as long as remainder of front legs 2. - [p. 350. 



2. Halteres chalk-white ". (ilbohalteralis, sp. n., 



Halteres not chalk-white 3. 



3. Upper branch of 4th vein abbreviated 4. 



Upper branch of4th vein reaching winsr-margin 6. 



* See Howlett, Ent. Montli. Mag. xhii, p. 229; Lundbeck, Dipt, Danica 

 pt. 3, p. 83; Aldricli, Arner. Natur. xxxiii, p. 809; Ha mm, Ent. Month. Mug 

 <2) xix, p. 181, and (2) xx, pp. 132, 157. 



