34 



MEMOIBS OF THE QUEENSLAND MUSEUM. 



Thorax. — The thorax is similar to that of the male (fig. 2). The form 

 of the last tarsus is shown in fig. 28. 



Wings. — As in the case of M. hilli there are slight differences in the 

 sexes in regard to the wing, particularly in the region of the first posterior 

 €ell and the posterior cross- vein (fig. 18). 



Abdomen (fig. 2). — The general colour is yellow with a brown median 

 dorsal stripe, rather broad on the anterior portion of the first segment and 

 more or less interrupted in the middle portion, but on the posterior region of 

 that segment the colouration makes its reappearance extending on to the 

 succeeding segment and widening to form a large dark-brown blotch of more 

 or less triangular outline. A similar patch of colour occurs on the succeeding 

 segment and is continued on to the fourth. Faint shimmering whitish patches 

 occur laterally towards the posterior end of the abdomen. The under surface 

 is yellow. 



Text-fig. 13, Outlines of thorax (dorsal) to show chsetotaxy; M. dustralis; 14, 

 M. vetustissima; 15, M. terrte-regince ; 16, M. hilli. Lettering — a., acrostichal (inner dorso- 

 *entral) ; d.c, dorsocentral ; hu., humeral; i.a., intra-alar; np?., notopleural; p.a., postalar; 

 p./i. posthumeral; pr., presutural; p.s.d.c, presutural dorsocentral; s.a., supra-alar; sc, 

 scutellar. 



Breeding Habits. — The eggs are laid in eowdung or horsedung, each egg 

 measuring about 1 mm. in length by -25 mm. in breadth, being very similar to 

 that of the house-fly. In less than twenty-four hours the eggs hatch, the larva? 

 being in the first instar (fig. 42). Twenty-four hours later the first moult 

 occurs; the anterior spiracles each with six or seven processes appear (fig. 45). 

 while the posterior spiracles are in the form of two almost straight slits (fig. 43). 

 The second instar also lasts about twenty-four hours. In the third instar the 

 posterior spiracles take the form of three sinuous slits surrounded by a black 

 .chitinous D-shaped ring (fig. 44). The mature larva? are creamy white and 

 measure 9 to 10 mm. in length by 1-5 mm. in breadth. They leave the dung 



