316 THE entomologist's record. 



forms are peculiar to these countries that it is an indispensable 

 adjunct to Finot's work. In addition to these three important books, 

 a large number of pamphlets and articles appear frequently in various 

 entomological journals, which must be consulted by the student who 

 wishes to thoroughly familiarise himself with the European Orthoptera, 

 and these will be found quoted in the three works mentioned above. 



It must be borne in mind that the points emphasised in the 

 following pages are not always the purely scientific ones, but rather 

 those most easily observed, and that statements made, unless otherwise 

 indicated, apply to European forms only. 



Order: ORTHOPTERA. 



Section I : Dermaptera. 



Family : Forficulid^. 



In earwigs, the characters to be observed are, first, the number of 

 segments in the antenns ; secondly, the shape of the second segment 

 of the tarsi, which may be simple and cylindrical, or heart-shaped ; 

 thirdly, the development of the elytra, which may be entire and 

 hinged to the thorax, rudimentary, and entirely attached to the 

 thorax, or wanting altogether ; fourthly, the shape of the forceps of 

 the male, which may have the branches separate at the base, or 

 contiguous there, slender, cylindrical, or strongly flattened and dilated, 

 nearly straight, or strongly curved inwards, unarmed or furnished 

 with a varying number of teeth on the inner margin ; fifthly, the 

 shape of the pygidium, a small organ present in some earwigs at the 

 apex of the abdomen between the roots of the forceps ; this may have 

 a spine, or be produced prominently forward between the forceps, and 

 sometimes assumes curious shapes ; sixthly, the shape of the subanal 

 plate, or last ventral segment, and also of the segment preceding it ; 

 the subanal plate may be rounded, as is normal, or strongly produced 

 into different shapes. 



On capturing an earwig, the collector will do well to first examine 

 whether the elytra and wings are perfectly developed. If they are 

 both rudimentary, the specimens must be either Aiii.wlabis or Chelidura, 

 which genera are not likely to be confused ; if, again, the organs of 

 flight are well developed, the second segment of the tarsus must be 

 observed ; if this is simple and cylindrical, it must be a Labia or a 

 Lahidura : in the former, the antennte have at least 16 segments, and 

 in the latter never more than 16 ; Labia, too, is easily known by its 

 small size and by the spine on the pygidium of the male. If the 

 second tarsal segment is not cylindrical, it is swollen at the end in the 

 form of a heart. The existence of this character is the mark of the 

 group Forficulae : if the specimen is a male, next examine the forceps ; 

 if the branches of this organ are broadened and flattened at the base, it is 

 a true Fur/icida; if not, either an Anechura, which has the forceps bent 

 downwards and the elytra and wings spotted, or an Aptenjyida, in 

 which case it will be entirely pale brown or uniform reddish in colour. 

 The last genus of this group has the elytra rudimentary or absent, and 

 the wings absent. This is Chdidara, always dark in colour, with the 

 abdomen broadened, especially towards the apex. 



It is extremely difficult to determine solitary females. The generic 

 characters of Furjicula and Apteri/i/ida are present only in the males, 

 and females of these genera, and of Anechura, are very easily confused. 



