266 The Orders of Insects 



broad at the hinder end and tapering forwards. They breathe by 

 means of large paired spiracles (fig. 147 c) on the tall-segment; the 

 fan-shaped spiracles on the prothorax (fig. 147 6) are probably not 

 used by the maggot, but air-openings In the same region become 

 functional in the pupa. The maggots in many genera are hatched 

 out within the mother's body; they feed on decaying animal and 

 vegetable substances, or are parasitic in caterpillars and other 

 insects wherein the mother - fly lays her eggs. The Muscidje 

 are world-wide in their range. The four divisions here char- 

 acterised as sub-families are regarded as families by most modern 

 authors. 



The TachinhiiE have strong bristles (macrocheta) on each of the four 

 to six hind-body segments, and the antennal bristle is naked or only 

 feebly pubescent. The larvs are parasitic on caterpillars. The 

 Dexirice, which also have parasitic maggots, are characterised by 

 strong bristles on their four-segmented hind-body and an antennal 

 bristle feathered to the tip. The Sarcophagina also have strong 

 bristles on the four-segmented abdomen ; the antennal bristle is 

 feathered for its basal half, and the larvje feed on decaying animal 

 matter. The Miiscirne have the hind-body devoid of stiff bristles, and 

 the antennal bristle is feathered throughout its length. 



Anthomyidse. — The Anthomy'uia: agree with the Muscids in hav- 

 ing scales behind the wings, but may be readily distinguished by 

 the ulnar nervure having a straight or evenly curved course, never 

 bending upwards at a marked angle towards the radial. The 

 antennal bristle may be' naked or feathered, and four or five hind- 

 body segments are visible. The larvje are flattened maggots often 

 with pointed tubercles on the segments; like the maggots of the 

 Muscids, they breathe by a pair of tail-spiracles. They feed in 

 decaying animal or vegetable substances, or devour living plant 

 tissues. The family is very numerous in genera and species and is 

 universally distributed (154). 



Tephritidae. — The Tephrhldts differ from the two preceding 

 families in the absence of scales behind the wings ; the neuration in 

 most of the genera resembles that of the Anthomyida;. The very 

 large section here treated as a single family was formerly regarded 

 as a sub-family of the Muscidse (Acalypterse) ; by many modern 

 authors, on account of the structural details showing great variation, 

 it is broken up into some fifteen distinct families. The larv2 are 

 mostly fleshy, tapering maggots, which live on decaying matter or 

 feed in living plant tissues, while some are parasitic on other insects. 

 The family is world-wide in its range. 



Phoridae. — The Phoridus are a family of small flies characterised 

 by the insertion of their short feelers close to tlie edge of the mouth. 

 The legs have long haunches, wide thighs, and very long basal 

 segments to the feet. The wings are relatively large and have a 

 very characteristic neuration ; two thick nervures — sub-costal and 

 radial — run close to the costa for about half its length and then 



