43 



On its anterior face the endosternite is connected 

 with the narrow plate-like second thoracic endopleurite 

 (/.). Near the point of junction of these two plates the 

 dorsal and articular borders are prolonged backwards as 

 rod-shaped pieces, each of which comes into contact with 

 anterior rod-like outgrowths from the corresponding 

 borders of the third thoracic endopleurite. 



The endopleurite arises betwen the third and fourth 

 epimera. It gives off two short anterior rod-like 

 prolongations from the dorsal and articular borders which 

 fuse with the rod-like extensions of the endosternite 

 mentioned above. The main part of the endopleurite, 

 however, consists of a broad plate, which passes backwards 

 and fuses with the fourth thoracic arthrophragm (e.). 



Second thoracic arthrophragm (Text fig. 7, D.}. 

 The endosternite is much more reduced than that of the 

 third thoracic arthrophragm. It arises from the 

 upturned edge of the sternum in this somite, and has a 

 very irregular shape. Its inner portion passes upwards, 

 and fuses with a narrow membranous process projecting 

 downwards from the last cephalic endopleurite (&.). 



The articular border is prolonged outwards as a rod- 

 like process, which fuses with the extremely small 

 articular border of the endopleurite of the same arthro- 

 phragm. About half way along the articular border the 

 endosternite fuses with a posterior rod-like extension of 

 the first thoracic endopleurite (d.). 



The endopleurite of this arthrophragm is a deep 

 narrow plate arising at the junction of the second and 

 third thoracic epimera. From its lower end it sends 

 forward a short process which fuses with the outer part of 

 the endosternite. The main part of the endopleurite 

 passes backwards and becomes fused with the third 

 thoracic endosternite (C.}, as described above. 



