20 



ORTHOPTERA OF .NORTHEASTERN AMERICA. 



cipal veins correspond in position to those of the tegmina, and 

 have the same names. Both tegmina and wings are wanting in a 

 number of species of Orthoptera, while in others the tegmina are 

 present and the wings absent. 



The legs of a locust are six in number, arranged in pairs, one 

 pair being joined to each of the divisions of the thorax. The first 

 and second pairs are, in the leaping Orthoptera, much smaller 

 than the third, but the number and name of the joints is the same. 

 They unite with the body at a different angle from the hind or 

 third pair, and are therefore adapted to crawling and clinging to 

 grass stems or other support rather than to leaping. 



The hind pair or leaping legs of 

 the locust are composed of five 

 parts: The coxa (c), or basal divi- 

 sion, which is joined to the meta- 

 thorax; a small segment, the tro- 

 c ha ntcr (tr), immovably joined to 

 the upper apical portion of the 

 coxa; the femur (f), a long, swol- 

 len, club-shaped segment, which 

 makes up nearly half the length of 

 the limb. \Yhen the insect is a I 

 rest, it extends upward and back- 

 ward, Avith its apical end above the 

 dorsal surface of the body. This segment contains powerful leap- 

 ing muscles. The tibia (ti) is about as long as the femur but is 

 very slender and of uniform diameter. When at rest it extends 

 downward and backward, at an acute angle from the apex or 

 knee of the femur, but in the act of jumping it is jerked backward 

 against the ground or other support, into which the tibial spurs 

 are driven, then the sudden straightening of the legs by the power- 

 ful internal muscles propels the insect into the air. In leaping 

 the tibia is kept from wobbling by a lobe extending back each 

 side of its base, from the apex of the femur. The tibia usually 

 bears on each of its upper outer margins a row of spines, and at 

 the end one or more pairs of longer spines or spurs known as 

 calcaria. The tibiae of the fore legs of a number of Orthoptera 

 are much modified for use in burrowing or prehending food. The 

 tdrxiis (td~) or foot of the locust is made up of three movable 

 joints. 4 The first and longest has upon its lower surface a soft 



Fig. ii. Hind leg of a locust, 

 ter Lugger.) 



(Af- 



4 In the grouse locusts or Tetrigidae and the sand crickets or Tridactylinre the fore and 

 middle tarsi have but two joints, while the tarsi of most Tettigoniidre have four and 

 those of the Blattidre, Mantidre and Phasmida; five. 



