612 EXTERNAL ANATOMY OF INSECTS. 



few, and some are without any 3 , and these terminate 

 those of this section of the Order in which the nervures 

 in question are continued to the margin of the wing. We 

 next come to those, Darnis, Centrotus, Me?nbracis, &c, 

 in which they are circumscribed a little within the apex by 

 a traversing nervure, so that the tegmen ends in a margin 

 of pure membrane, and thus some approach seems to be 

 made to the Hemelytra, from Tettigonia, the most con- 

 spicuous genus of this tribe, in which the areolels, few in 

 number, like those of Lepidoptera, are not formed, except 

 the terminal ones, by traversing nervures, but by the 

 ramifications of the longitudinal ones ; in Chermes the In- 

 termediate Area, which is connected with the base of the 

 wing by a single nervure, is the only part that has any 

 areolets b . 



7. Colour. Orthopterous insects are seldom remark- 

 able for tegmina of brilliant colours-, there is in them none 

 of that gilding or metallic lustre which so often distin- 

 guishes elytra: they are also frequently less ornamented in 

 this respect than the wings, with which they usually form 

 an agreeable contrast. Their reticulations and nervures, 

 which are sometimes of a different colour from the rest 

 of the tegmen, decorate them considerably : a remarka- 

 ble circumstance belonging to this head attends the black 

 tegmina of Blatta Petiveriana ; one has four white spots, 

 and the other only three; but as one laps over the other, 

 the symmetry of the arrangement is preserved : the Ho- 

 mopterous Hemiptera are more distinguished in this re- 

 spect, and some of the Fulgoridcs imitate the Lepidoptera 

 both by their ocelli and spots : Fulgora laternaria^ Can- 



J Of this kind is one of StolPs Cigales, t. xxv./. 141. 

 |J Plate XXVIII. Fig. 18 



