THORACIC APPENDAGES 159 



i. The two protopodites are fused in the median 

 plane to form a two-jointed plate. The sub- 

 mentnm or proximal joint is the larger of the 

 two, and is very broad from side to side. The 

 distal joint, or mentxun, is smaller, and bears 

 the endopodites and exopodites. 



ii. The endopodites are together sometimes called 

 the ligula. Each is divided into an outer 

 division, the paraglossa, corresponding to the 

 galea of the first maxilla ; and an inner divi- 

 sion, corresponding to the lacinia. 



iii. The exopodites are three -jointed palps corre- 

 sponding in form and position to those of the 

 first maxillsB. The stump supporting each is 

 called the palpiger. 



2. The thoracic appendages are three pairs of legs, borne 

 by the sterna of the thoracic segments. They are 

 very similar to one another, but the hindmost are 

 rather the largest. Each leg consists of the following 

 parts. 



a. The coxa is the stout, flat, pfoximal joint of each 



leg. 



b. The trochanter is a very small piece attached to the 



distal end of the coxa. 

 0. The femur resembles the coxa in form, but is more 

 slender. 



d. The tibia is a slender straight joint armed with 



strong spines. 



e. The tarsus, or foot, is six-jointed, each joint having 



a soft white setose patch under its distal end, 

 giving the animal a foothold in climbing steep or 

 slippery surfaces. The terminal joint or pul villus 

 is small and bears a pair of claws. 



3. Abdominil appendages are very rare amongst adult 

 insects. The anal cerei already described, and pos- 

 sibly also the styles on the ninth sternum of the 

 male, may be appendages, as also may the gon- 



