162 THE entomologist's record. 



hole they make use of their legs in a somewhat unusual order, viz., 

 leaning over to one side and fixing the three legs of that side in the 

 sand, they drive out the sand by a rapid action of the three legs of the 

 other side, doing this alternately on either side, and advancing into 

 the hole a short way at each alternation. — T. A. Chapman, M.D., 

 Betula, Reigate. 



<g)RTHOPTERA. 



Abbreviation of Wings in Orthoptera. 



By MALCOLM BUER, F.Z.S., F.E.S. 

 [('oncliidcil fmui p. 103.) 



One effect of the abbreviation of wings is that the form of the 

 pronotum is correspondingly changed. In earwigs, for instance, the 

 hinder border is rounded in tbose species which have fully developed 

 elytra and wings, whereas in the apterous forms the hinder border is 

 straight, and often shows a few faint longitudinal sutures. 



But it is in the Pha-viKidca that the abbreviation of the organs of 

 flight is carried to the greatest extreme, while its effect upon the 

 somites gives the systematist a most valuable character. In his great 

 work on this group, published in 1859, Westwood divided the family 

 into two sections, according as they had, or had not, organs of flight. 

 A study of his plates will show at a glance that heterogeneous species 

 are ranged in the same genus. But although the actual development, 

 abortion, or absence of flight-organs is a useless character for the 

 systematist, the form of what is known as the median segment is 

 invaluable. On this point Brunner writes : — " What is usually regarded 

 as the third segment of the thorax, is a close fusion of the metathorax 

 with the first abdominal segment, and this first abdominal segment 

 has received the name ' median segment.' " He goes on to show that 

 the exact point of division is not always easy to see. Further, in the 

 winged species the median segment encroaches considerably on the 

 metanotum, with the result that the latter only occupies a third of the 

 total length of the combined segment ; while in the wingless forms, 

 on the contrary, it is the median segment which only occupies a third 

 of the total length of the combined segment. Therefore, by means of 

 this character, it is possible to fix the apterous females of those species 

 in which the males are winged, as the length of the segments is 

 uniform in the two sexes. Again, species which have lost the flight- 

 organs, can also be distinguished from completely apterous forms by 

 this character, as they retain the relative lengths of the two segments. 

 It folloAVS that the form of this median segment aftbrds us a character 

 far more pregnant than the presence or absence of wings. 



There is another point to notice in connection with the Fhasmodea. 

 In Orthoptera generally, it is usually the wings which decline, leaving 

 the elytra. This, of course can" be explained in the saltatorial groups 

 by the retention of the latter for stridulating purposes in the male, 

 whence they are transferred to the female. But in the I'hoKinodea the 

 elytra go first, and are invariably smaller than the wings. In the 

 Aschiphaaw iliac the elytra are reduced to tiny lobes, or even mere spines, 

 while the wings, large and fanlike, extend the Avhole length of the 

 abdomen. When closed they have no horny elytra to protect them, 



