THE INSECTA. 121 



Metamorphosis is complete ; a quiescent pupal condition 

 being interposed between the larval and the imaginal states. 



The Ant-lions, Lace-flies, and Scorpion-flies are included under 

 this division. 



Of the remaining insects, which have an incomplete meta- 

 morphosis and masticatory jaws, many have been included under 

 the head of 



4. OKTHOPTERA. But the assemblage is a very miscel- 

 laneous one, and contains a number of remarkably different 

 types, of which the chief are 



a. The restricted Orfhoptera, which have the anterior 

 wings coriaceous and elytra-like, the posterior wings mem- 

 branous an 1 } folded. 



These are the Cockroaches, Mantides, Leaf and Stick 

 Insects, Grasshoppers and Locusts. 



b. The Dermatoptera. The anterior wings are converted 

 into elytra ; the posterior membranous and doubly folded. 



The Earwings alone are contained in this group. 



c. The Corrodentia, or Termitinse, have the fore and 

 the hind wings similar and not folded. 



The genus Termes, which belongs to this division, in- 

 cludes the so-called " White Ants," whose destructive 

 ravages are so well known in tropical countries. Besides 

 sexual individuals, there are two sexless forms, termed 

 "soldiers" and "workers." The male and female Ter- 

 mites alone have wings. The hinder wings are not folded, 

 and both pairs fall off after copulation. 



d. The Perlarise have membranous hairy wings, the pos- 

 terior folded lengthwise ; and aquatic larvae, with more or 

 less distinct tracheal gills. 



e. The Ephemeridae, or Day-flies, have the jaws rudi- 

 mentary ; the posterior wings not folded, much smaller 

 than the anterior, or absent. 



The larvae are carnivorous, with well-developed jaws and 

 tracheal gills. The imagines undergo ecdysis after leaving 

 the pupa, in which circumstance they stand alone among 

 insects. 



