DIPTERA. 417 



The True Nematocera. The antennae usually long and frequently 

 bearing whorls of long hairs, especially in the males ; legs long 

 and slender; abdomen usually long and slender. 

 77/6' Moth-like Flies, Family PSYCHODID^E. p. 428. 

 The Midge-like Flies. 



The Crane-flies, Family TIPULID^E. p. 429. 

 The Net-winged Midges, Family BLEPHAROCERID^E, p. 432. 

 The Dixa-midges, Family DIXID^E. p. 436. 

 The Mosquitoes, Family CULICID.E. p. 437. 

 The Midges, Family CniRONOMlDyE. p. 440. 

 The Fungus-gnats, Family MYCETOPHILID/E. p. 442. 

 The Gall-gnats, Family CECIDOMYIID/E. p. 444. 

 The Anomalous Nematocera. The antennae are composed of 

 many segments, but are shorter than the thorax, and without 

 whorls of long hairs. The segments of the antennae are short 

 and broad and closely pressed together. Except in the first 

 family, the abdomen is comparatively stout, and the legs are 

 shorter and stouter than in the True Nematocera. 

 The False Crane-flies, Family RHYPHID^:. p. 448. 

 The Solitary-midge, Family ORPHNEPHILID^E. p. 449. 

 The March-flies, Family BIBIONID/E. p. 449. 

 The Black-flies, Family SIMULIID^:. p. 451. 



The Short -horned Orthorrhapha or Brachycera (Bra-chyc'e-ra). 

 Orthorrhapha with one- or two-jointed, porrect palpi, and with 

 usually short, three-jointed antennae. The third segment of the 

 antenna is sometimes distinctly ringed, showing that it is really 

 composed of many segments grown together ; and sometimes 

 the antennae are four- or five-jointed. 



The Anomalous Brachycera. The third segment of the antenna is 

 ringed, showing that it is composed of several segments grown 

 together. The body is not furnished with strong bristles. 

 The Horse-flies, Family TABANIDA;. p. 453. 



occur in those families grouped below as the Anomalous Brachycera (see 

 Figs. 489, 490, and 492). The Nematocera and Brachycera are more 

 sharply distinguished by the form of the palpi, as indicated in this Synopsis ; 

 but sometimes it is difficult to see the palpi. A more easily seen distinction 

 is presented by the venation of the wings. In the Anomalous Brachycera 

 cell V 2 is divided by a cross-vein and cell VIII is closed before the margin of 

 the wing or is greatly narrowed at the margin of the wing (see Figs. 539, 

 545, and 551). In the Nematocera cell VIII is never closed, and cell V 2 is 

 divided only in the Tipulidse and Rhyphidse, and in these families the 

 antennae are distinctly composed of many segments. 



