28 



BEITISH BEETLES. 



abdomen also contains the greater number of spiracles, 



or breathing-holes, situated in 

 a row on the upper surface of 

 the sides ; these spiracles, nine 

 or ten in number, are placed 

 as follows : one, the largest, 

 between the prothorax and 

 mesothorax; another between 

 the mesothorax and metathorax, 

 covered in repose by the wing- 

 cases, but exposed in flight; 

 a third between the metatho- 

 rax and first segment of the 

 abdomen, and the remainder 



between every two of the other abdominal rings, with 



the exception of the last pair. 



Fig. 11. 



Under side of abdomen of 

 D. marginalis. 



