THE LEGS: THEIR STRUCTURE AND FUNCTIONS 95 



TABULAR VIEW OF THE SEGMENTS, PIECES, AND APPENDAGES OF 



THE THORAX 



NAME OF SEGMENT 



PIECES 



1. Prothorax 



2. Mesothorax 



3. Metathorax 



Pronotum, sometimes 



differentiated into 

 Scutum 

 Scutellum 

 Episternum 

 Epimerum 

 Sternum 

 Antefurca 



Prtescutum 



Scutum 



Scutellum 



Proscutellum 



Episternum 



Epimerum 



Sternum 



Mesofurca 



Mesophragma 



Apodemes 



Prtescutum 



Scutum 



Scutellum 



Postscutellum 



Episternum 



Epimerum 



Sternum 



Postfurca 



Metaphragma 



Apodemes 



Al'I'ENDAGES 



1st pair of legs 



Patagia 



2d pair of legs 

 1st pair of wings 

 Tegulse 



Squamae (Alulse) 

 Peritreme 



3d pair of legs 

 2d pair of wings 

 (Halteres of Diptera) 



b. The legs : their structure and functions 



The mode of insertion of the legs to the thorax is seen in Pigs. 90, 

 97, 101, and 103. They are articulated to the episternnm, epimerum, 

 and sternum, taken together, and consist of five segments. The 

 basal segment or joint is the coxa, situated between the episternum 

 and trochanter. The coxa usually has a posterior subdivision or 

 projection, the troi-lnmtine ; sometimes, as in Mantispa (Fig. 103), the 

 trochantine is obsolete. We had previously supposed that the tro- 

 chantine was a separate joint, but now doubt whether it represents 

 a distinct segment of the leg, and regard it as only a subdivision of 



