216 SYSTEMATIC ARRANGEMENT. 



gate, probably exceeding every other assemblage a, 

 the insect tribes. In this country, not more than 

 about fifty indigenous Orthoptera have hitherto been 

 detected, and it is not likely that any considerable 

 number have escaped the researches of modern 

 collectors. 



Although these insects must, of course, present a 

 pretty general agreement in all essential parts of 

 structure sufficient to justify their arrangement in the 

 same division of their class, they are certainly very 

 dissimilar in external aspect. The genera For- 

 ficula, Blatta, Locusta, and Phasma, bear almost as 

 little outward resemblance to each other as the species 

 of any two separate orders. It was this circumstance 

 that led Dr. Leach to propose its division into three 

 different orders, Dermaptera, including Forficula; 

 Dictyoptera, including Blatta, and distinguished by 

 the tegmina overlapping each other on the back; 

 the other tribes to be referred to Orthoptera. The 

 first of these has been since admitted by some authors 

 to the rank of a separate order ; among others, by 

 Mr. Westwood, who names it Euplexoptera, because 

 the term Dermaptera is said to have been completely 

 misapplied by English Entomologists, having been 

 originally proposed for the Cimicidse. Notwithstand- 

 ing the peculiarities in its structure which have led 

 to this step, it is difficult, we think, to examine the 

 earwig without being convinced that it is essentially 

 an Orthopterous insect; and as that order must, in 

 any case, be defined with considerable latitude, it 

 can scarcely be regarded as an undue extension of it 



