856 AN INTRODUCTION TO ENTOMOLOGY 



monographed by Cresson ('20) and also by Melander ('20a) under 

 the name Tetaroceridae. 



Family SAPROMYZID^ 



The head is as broad as or a Httle broader than the thorax; the 

 legs are of moderate length; the hind tibiae bear a preapical bristle; 

 the abdomen is short ; the ovipositor is neither flat nor drawn out ; the 

 subcostal vein is distinctly separated from vein Ri and ends in the 

 costa; vein 2d A does not reach the margin of the wing; the oral vi- 

 brissas are absent; the second antennal segment bears a dorsal bristle ; 

 the postvertical bristles are convergent ; and one or more stemopleural 

 and a mesopleural bristle are present. 



This family is composed of small flies, which are seldom more than 

 7 mjn. in length. Nearly one hundred species have been described 

 from America north of Mexico. A synopsis of the family was pub- 

 lished by Melander ('13 a). 



The larvae of Sapromyza live in decaying vegetable matter. 



This family is named the Lauxanidae by some writers. 



The family LONCH^ID^E includes the genera LonchcBa and 

 Palloptera, which are included in the Sapromyzidae by some writers. 

 These genera differ from the Sapromyzidae in that the hind tibiae are 

 without a preapical bristle; and the ovipositor is flattened and more 

 or less projecting. A synopsis of our species is included in Melander 



('13a). 



Lonchcea polUa has been reared from a decaying fungus {Polyporus) 

 and from human excrement. 



Family ORTALID^ 



This family like the Trypetidse is a large one and contains many 

 common species which have the wings beautifully marked with dark 

 spots or bands. The members of this family differ from the Trypetidas 

 in that the subcostal vein extends to the margin of the wing in the 

 usual way and in that the lower fronto-orbital bristles are wanting. 



Comparatively few species of the Ortalidas have been bred and 

 these differ greatly in habits. The larvae of some have been found 

 under bark of dead trees, others in excrement, some are parasitic on 

 lepidopterous larvae, and several infest growing plants. Among the 

 latter are Chcetopsis csnea and Tritoxa flexa which sometimes infest 

 onions; but the most important onion maggot is Hylemyia antiqua 

 of the family Anthomyiidae. 



The family includes six subfamilies each of which is given family 

 rank by Hendel ('22). 



Family TRYPETID^ 



This is a very large family including many common species 

 with pictured wings, in which it resembles the preceding family, the 



