STKUCTUEE. 7 



(127), as well as the Neuropfcera ^schna (119), 'Agrion (121), and 

 examples of large water-boatmen (145, 147). 



In other cases the three stages are strongly marked (as, for 

 example, the caterpillar and chrysalis of a moth). In such cases 

 the insect is said to undergo complete metamorphosis. 



Specimens of the larva, pupa and imago of a common water- 



Fig. 3. 



Larva, pupa and imago of a common English water-beetle, Dytiscus 

 marginalis. (1010.) 



.beetle (Dytiscus marginalis, 1010, fig. 3) are shown in Table-case 29. 

 Other examples of Coleoptera (1 29-143), of Neuroptera (111-11 7), of 

 Lepidoptera (109), of Hymenoptera (101-105), and larvae of Diptera 

 (107) are shown in Wall-case 8. 



In Table-case 30 is a series of insects showing examples of the Table- 

 different Orders, with labels indicating their principal characters, case30 - 

 These are not arranged in a line, but (as far as can be) in accordance 



