20 



The tergum of the prothorax is frequently called 't'hie/r'^-* 

 notum ; the tergum of the mesothorax, the mesonotum j aricf 

 that of the metathorax, the metanotum. 



There are in this insect two pairs of thoracic spiracles. 



APPENDAGES OF THE THORAX. 



The appendages of the thorax are the legs and the wings ; 

 the number and distribution of these have already been given! 



Legs. — Examine the ventral aspect of the first pair^o^ 

 legs. Each leg will be found to consist of the 'following 

 named parts : — 



Coxa. — This is the proximal segment of the leg. If is sub- 

 globular in outline. Examine the cephalic aspect of the coxa, 

 and note the longitudinal suture which traverses this side b£ 

 it ; this is shown better on the mesothoracic legs. 



Trochanter. — This is the second segment of the leg, and is 

 much smaller than the coxa. The ventral aspect of it is 

 much longer than the dorsal. 



Femur. — This is the third and principal segment of the 



leg. " , ', , 



Tibia. — This is the fourth segment of the leg. It nearly 

 equals the femur in length, but is more slender. 



Tarsus. — The tarsus include-s all of that part of the leg 

 distad of the tibia. It consists in locusts of three segments.' 



The last segment of the tarsus bears a pair of claws'. 



On the ventral surface of the tarsus there is a' series of 

 cushions , these are called pulvilli. The distal segment of 

 the tarsus bears a single pulvillus which projects between 

 the claws , this is often referred to in descriptive works as 

 the pulvillus. ' 



•Note. — In the membrane connecting the coxa with the thorax just ceph- 

 alad of the coxa, is a sclerite , this we beheve to be the trochantin The 

 trochantin is a sclerite which is considered to be an appendage of the coxa/ 

 and its normal position is between the coxa and the antecoxal piece 



