2l6 ORTHOPTERA 



matists ; no arrangement into sub-families or groups of greater 

 importance than genera is adopted. 



The only particulars we have as to the embryological develop- 

 ment of the earwig are due to Heymons. 1 The forceps spring 

 from the eleventh abdominal segment, and 

 represent the cerci of other Orthoptera. An 

 egg-tooth is found to be present on the 

 head for piercing the egg-shell. The embryo 

 T reverses its curved position during the de- 

 velopment, as other Orthoptera have been 

 observed to do, but in a somewhat different 

 manner, analogous to that of the Myriapods. 

 Several fossil Forficulidae are known; 

 specimens belonging to a peculiar genus 

 have been described from the Lower Lias of 

 *Aargau and from the Jurassic strata in 

 FIG. us.-AnisoKMstas- Eastern Siberia, but the examples appar- 



ittfCt/llCCv O 



ently are not in a very satisfactory state of 

 preservation. In the Tertiary formations earwigs have been 

 found more frequently. Scudder has described eleven species of 

 one peculiar genus from the Lower Miocene beds at Florissant in 

 Colorado ; some of these specimens have been found with the 

 wings expanded, and no doubt that they were fully developed 

 Forficulidae can exist. The fossil species of earwigs as yet known 

 do not display so remarkable a development of the forceps as 

 existing forms do. 



Brauer and others treat the Forficulidae as a separate Order 

 of Insects Dermaptera but the only structural characters 

 that can be pointed out as special to the group are the peculiar 

 form of the tegmina and hind wings which latter, as we have 

 said on p. 206, are considered by some to be formed on essentially 

 the same plan as those of other Orthoptera the imbrication of 

 the segments, and the forceps terminating the body. The develop- 

 ment, so far as it is known, is that of the normal Orthoptera. 

 Thus the Forficulidae are a very distinct division of Orthoptera, 

 the characters that separate them being comparatively slight, 

 though there are no intermediate forms. Some of those who treat 

 the Dermaptera as a sub -Order equivalent to the rest of the 

 divisions of the Order, call the latter combination Euorthoptera. 

 1 SB. Ges. naturf. Fr. Berlin, 1893, p. 127. 



