METAZOA INSECTA. 411 



are not so extremely modified as many among the more 

 specialized orders, such as, for instance, Melophagus ovi- 

 nus Linn., the sheep-tick of the Diptera. The Mallo- 

 phaga still have the generalized type of mouth parts and 

 the power of locomotion. 



Order 6. EUPLEXOPTERA. 



The larval characters of this order are mostly primi- 

 tive and generalized, but little is known of the develop- 

 ment or life history of the group. 



Unlike most insects the mother earwig does not die 

 soon after laying her eggs, but according to Kirby she 

 broods "over her eggs and young almost like a hen." 1 



PI. looo, fig. i, is the larva of the common earwig, 

 Forficula auriciilana Linn. The thorax and abdomen 

 are distinctly segmented, and the junction of the two is 

 broad. The caudal appendages, even at this early stage, 

 are in the form of forceps. 



The adult (PI. 1000, fig. 2 ; No. 1001) retains the long 

 body of the larva, the distinct thoracic segments, and the 

 biting mouth parts. There is a peculiar imbricated ar- 

 rangement of the segments, however, which we have not 

 seen in the insects so far described. 



The wings of the adult are unique. The anterior pair 

 are reduced in size and are chitinous covers for the hind 

 wings, which are large and rounded when spread (PI. 

 1000, fig. 3), but which by an ingenious method can be 

 folded and almost wholly packed away under the wing 

 covers (fig. 4) ; hence the name of the order Euplexop- 

 tera, meaning to fold well and wing. The projecting por- 

 tions of the wings, unlike the remaining parts, have the 

 same texture and sculpturing as the wing covers. 



No one knows what has caused the earwig to fold its 



1 Text-book of Ent., 1885, p. 81. 



