terminal fiegmciit i)i some male Hemiptera. -417 



merely projects as a short horizontal process, termi- 

 nating in the middle of the posterior chamber. In 

 Edessa it extends the whole length of the segment along 

 its middle, the orifice of the cauda being closed by appo- 

 sition with the floor of the chamber at the part I have 

 called the lip. In this genus, as well as in Nezara and 

 Catacanthus, the cauda is ornamented by thickened pro- 

 cesses or bosses, which are frequently covered with 

 symmetrically curved cilise. 



Excepting only in Poecilochroma lata, the cauda covers 

 up the oedeagus, and for this purpose its under face is 

 very peculiarly formed, being hollowed by a large cavity, 

 the lips of which differ much in form and other respects 

 in different species. In those genera where the cauda 

 is elongate, Nezara and Edessa, e. g., it so completely 

 encloses the cedeagus that that organ can only be 

 brought into use when the cauda is got out of the way ; 

 for this purpose it is capable of elevation, and of being 

 retracted to a considerable extent into the anterior 

 chamber. The species of Edessa I have examined, 

 notably E. rufo-marginata, afford a good illustration of 

 this peculiarity. 



In the Plataspince the cauda forms a curious rounded, 

 very slightly elevated, process, having no apparent 

 orifice, owing to this being curved forwards and applied 

 to the face of the segment, and protected beneath by a 

 small carina. 



Although I do not entertain any doubt as to the cauda 

 being really the terminal portion of the alimentary 

 canal, it is, perhaps, well to say that I have not verified 

 this by tracing it forwards into the abdominal cavity. 



The lateral appendages. — Although constantly present 

 in the Pentatomidm, these appendages are not alike in 

 form in any two species, and they, in fact, differ so 

 extremely in their shapes that it is almost impossible to 

 say anything of a general character as to this point. 

 Their position is, however, constant, one on each side of 

 the rectal-cauda, and frequently curving round behind its 

 extremity. The anterior parts of the lateral appendages 

 penetrate through or under the diaphragm, where their 

 extremities are connected together by means of a strong 

 ligament, which passes immediately behind, and presses 

 on, the theca of the cedeagus. The lateral appendages 

 are of very large size in the species of Tesseratoma and 



2 F 2 



