terminal segment in some male Hemiptera. 405 



that the propriety of placing the two insects in the same 

 subfamily may be doubted ; the segment is, in fact, quite 

 different in its plan from any other Pentatomid I have 

 seen, and seems to approach in some respects the family 

 Pyrrhocorida. When the hemi-elytra are opened and 

 the insect first inspected it seems as if all the parts were 

 absent ; the floor of the terminal chamber projects 

 backwards, and its sides are curved upwards so that an 

 imperfect cavity is formed, and all that can be seen is a 

 transverse projection on the upper part of the anterior 

 wall of this very open cavity. This is, however, due to 

 the very great retractility of the terminal segment, and 

 when the segment is extended to its full length, it is seen 

 that the anterior part, which was covered during re- 

 traction by the preceding segment of the body, is the 

 true terminal chamber, and the part behind it that was 

 exposed is merely an adventitious growth. The orifice 

 of the true terminal chamber looks directly upwards, 

 but does not occupy a,nything like the whole of the upper 

 aspect of the chamber, but is confined to an oval space 

 on its centre ; the orifice, too, is in larger part tilled up 

 by the rectal- cauda, which is not at all deflexed, but 

 forms a horizontal roof in the position I have mentioned: 

 immediately behind it there are two small projections 

 nearly meeting in the middle ; these are the lateral 

 appendages ; the projection I have alluded to previously 

 as seen on the upper part of the anterior wall of the 

 adventitious posterior cavity, it is now seen occupies the 

 position of the inferior process. Although it has the 

 form and somewhat the position of that part, as described 

 in the Tesseratominee, it differs in the important fact 

 that it is not articulated, and also, of course, in the fact 

 that it is placed altogether behind the lateral accessory 

 processes, instead of in front of their terminations. 



In considering the functions of the different parts 

 hereafter, I shall state that I consider the function of 

 the inferior lateral process to be that it determines the 

 exact direction to be taken by the oedeagus when it is 

 protruded, or rather deflexed. It is possible that the 

 projection I am now speaking of in P. subuhitam may 

 have this function, though I very much doubt it. 



On lifting up the rectal-cauda (and this is very easily 

 done when the specimen is duly relaxed) the very large 

 theca is seen occupying the greater part of the chamber, 



