148 A. HAMMOND ON A COMPARISON OF THE METAMORPHOSIS, &C. 



Fig. 6. — Section of the same perpendicular to the integument, showing the 

 continuity of the capsule (?) with the newly forming pupa skin 

 beneath that of the larva. 



Plate XI. 



Fig. 7. — The pupa of the Crane Fly shewing the superior prothoracic 

 appendages projecting from the thorax. The antennae are seen 

 bent down in front on each side of the head, and below are the 

 outlines of the wings and legs. 



Fig. 8. — The pupa of the Blow Fly, dorsal view shewing the superior 

 prothoracic appendages. 



Fig. 9. — The pupa case of the Blow Fly. 



Fig. 10. — The imaginal discs of the Blow Fly in connection with the nerve 

 centres and trachese. The greater part of this figure is adapted 

 from those in Mr. Lowne's monograph; it is introduced chiefly for 

 the purpose of illustrating my remarks on the position of the 

 superior prothoracic discs, which I submit are situated as repre- 

 sented at the anterior extremities of the tracheae, immediately 

 beneath the integument. The discs in the centre are the optic and 

 antennal, attached (?) to the nerve centres above, and those of the 

 anterior and intermediate legs below. The remaining discs 

 attached (?) to the trachese are those of the wings, halteres, and 

 posterior legs. 



Figures 1, 7, and 9 are slightly magnified ; the remainder are drawn under 

 an inch objective. 



