EXPLANATION OF FIGURE 30. 



Melanostoma mellinum Linne. 



1 Masses of eggs as deposited by female on leaf of rape xi2. 



2 Egg-mass from another female, showing the characteristic ranking of 

 eggs side by side, xi2. 



3 A small area of the egg-shell highly magnified, showing nature of 

 sculpturing. 



4 Ventral view of head-segments of larva much enlarged ; A, lateral 

 mouth-hook; B, antenna; C, upper jaw; D, anterior larval spiracle. 



5 End view of posterior respiratory organ x 175, showing the two 

 stigmal plates ; A, the carina bearing left, dorsal, slit-like spiracle ; 

 B, right circular plate ; C, one of the inter-spiracular nodules. 



6 Dorsal view of larva x 10; A, left longitudinal tracheal trunk; B, 

 antenna ; C, termination of the right tracheal trunk in the anterior 

 spiracle ; D, posterior respiratory organ. 



7 Dorsal view of puparium x 10; A, right pupal respiratory cornua 

 with trachea leading from it ; B, posterior larval respiratory organ. 

 The outline of head, thorax with wing-pads, and abdomen of the 

 developing fly show thru the puparium. 



8- Side view of pupal respiratory cornua, highly magnified. 



End view of pupal respiratory cornua with afferent trachea, highly 



magnified. 



10 Side view of head of adult $. 



// Wing. 



12 Abdomen of $. 



13 Posterior part of thorax and abdomen of <$■ 



