Zoology.] NATURAL HISTORY OF VICTORIA. [Insects. 



and the greater or less distinctness of the mottling or obscurity of the tip of the 

 hind wings. The two most distinct and persistent varieties are the common one, 

 with thorax, and hind margin of tegmina, pea-green, and the other with those parts 

 testaceous brown. The green is also sometimes absent from the thighs, which are 

 then brown, irregularly banded with darker. In other respects the varieties agree. 



Reference. — Gryllus musicus, Fabr. Ent. Syst., v. 2, p. 55 == Gryllus pieties, 

 Leach, Zool. Misc., v. 1, t. 25. 



The family Locustidce, or the true Locusts, embracing all the 

 migratory sorts, includes a number of genera differing from the 

 Gryllidoe, or Grasshoppers, in the females not having the long 

 exserted ovipositor ; and in having the antennae short, not half the 

 length of the body, and of only 20 to 30 joints, and either cylindrical 

 or fusiform or clavate in shape. The head has three ocelli, or 

 small simple eyes, usually, but never less than one, while they are 

 absent in the Grasshoppers. The tarsi are only 3-jointed, instead 

 of 4-jointed as in the Grasshoppers. The wings in the Locusts 

 never have the talc-like, eye-like stridulating organ at the base 

 of the right anterior wing or tegmen of the male, but produce 

 their song, or shirring chirp, by the totally different method of 

 rubbing the hind femora and tibiae against the hard anterior edge 

 of the deflexed anterior wings or tegmina, the insect standing on 

 the four anterior legs while rapidly scraping the thighs up and 

 down like the bow of a fiddle against the raised edge of the 

 wing- covers ; the thigh of one side being used alternately with 

 that of the other. 



Connected apparently with this mode of singing is another 

 structural peculiarity found in all Locusts (of both sexes), and not 

 in Grasshoppers ; this is a semi-oval drum-like cavity (see our 

 Fig. li) just above and behind the base of the hind leg on each 

 side in the last thoracic segment, with a bright reflecting internal 

 plate partially crossing the cavity ; the whole apparently intended 

 to increase the resonance of the sound produced by the scraping of 

 the hind legs on the wing-case edge. 



The great size of the muscular thighs of the posterior pair of 

 feet enables the Locusts to jump much higher, further, and more 

 readily than the Grasshoppers, giving an example of muscular 

 power almost unparalleled in the animal kingdom. The hind legs 

 are not used for walking, which is effected by the four anterior feet, 



[ «] 



