432 MODERN CLASSIFICATION OF INSEC:TS. 



ments is so slight, that entomologists have fallen into error respecting 

 it. Thus, in the winged individuals, the abdomen is stated by Brulle 

 to have ten dorsal segments ; whilst in the wingless species, and in the 

 \arvse, there are but nine dorsal segments ; but an attentive compari- 

 son between the more regularly developed metathorax of the latter 

 with the metathorax and supposed basal abdominal segment of the 

 former, clearly proves that the two last-mentioned segments are but 

 one segment, of which the anterior portion is more developed, in 

 order to give support to the wings, which are attached to it in front. 

 The dorsal surface of the abdomen, thus, in the individuals of both 

 sexes, consists of nine segments ; but on the ventral surface the three 

 terminal segments are i-epresented in the females by a single plate, 

 serving as a kind of ovipositor; thus, in the males, there are nine, 

 Avhilst in the females there are only seven, distinct ventral seg- 

 ments. 



All the legs are alike, being long and slender, often armed with 

 short spurs along the edges. The coxa* is of small size, and the 

 tarsi are simple and 5-jointed-|-, with the under side of the joints 

 clothed with a membranous cushion, enabling them to retain their 

 situation upon plants; the pulvillus between the ungues is also large. 

 In some species the femora are furnished with large, membranous, 

 flattened appendages ; and in many the base of the anterior femora is 

 curved so as to fit the head. This peculiarity is rendered necessary 

 by the habit of the insect when at rest, in stretching its legs forward in 

 a straight line, so as to defend the antennte. This is the position in 

 which L. Guilding represented the larva of P. cornutum. (^Linn. 

 Trans, vol. xiv. pi. 7. See my fig. 53.12.) 



The tegmina, or fore wings, are of small size|, and, when present, 

 are attached at the posterior part of the mesothorax. The true 

 wings, on the other hand, are very large, and attached to the anterior 

 part of the metathorax. As they far exceed the wing-covers in size, 

 it is essential that provision should be made for their defence. This 



* The elongation of the coxa? is one of the surest indications of predaceous habits, 

 giving to the leg a greatly increased degree of action. 



+ Percheron describes Bacteria rosaria as having onlj' four joints in the tarsi ; and 

 I possess a large apterous species, in which the anterior tarsi are only 4-jointcd, the 

 others bein 5- jointed. 



% In a preceding page, I have noticed the occurrence of a species belonging to 

 this family, in which the fore wings are entirely obsolete, whilst the hind wings are 

 of large size. 



