130 Invertebrate Zoology. 



of the legs are as follows : The coxa, short and ring-like, 

 bears at its free end the trochanter, which is a little smaller 

 than the coxa, to which, in the third leg, it becomes fused. 

 The trochanter bears a long joint, the femur, which, at its 

 free end, bears another long joint, the tibia. The tarsus 

 is made up of a series of small movable joints which bear 

 pads on their lower surfaces. The tarsus is terminated by 

 the claws. 



The fore-wings or wing-covers differ from the true wings. 

 Note the arrangement of their veins t the rib-like lines which 

 strengthen them and which are in communication with the 

 circulatory and tracheal system. The second or true-wings 

 are, when at rest, folded like a fan. Note the arrangement 

 of the veins and see if the wing-covers, when expanded, do 

 not support the anterior edge of the true-wings. 



The abdomen is composed of a series of ten segments or 

 metameres, all but the last two or three of which are very 

 evident. There are no abdominal appendages. 



The first abdominal segment is somewhat modified from 

 its association with the metathorax. Laterally, it is pierced 

 by two large openings, one on either side, which lead into 

 the auditory organs. The abdominal segments of the two 

 sexes from the first to the eighth closely resemble each 

 other. 



The ninth abdominal segment of the female is only about 

 one-fourth as wide as the eighth, and is not provided with an 

 independent sternal piece, the sternum of the eighth extend- 

 ing to the posterior end of the mid-ventral line. The pos- 

 terior edge of the tenth abdominal segment follows a line 

 parallel with posterior edge of the eighth. There project 

 posteriorly from the tenth segment a series of more or less 

 flexible pieces of which the dorsal is the larger and may 



