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ENTOMOLOGICAL SOCIETY 



an arm-like process anteriorly parallel with the wing process, 

 and has an internal disc-like surface (MD) for the attachment 

 of the principal pronator muscles of the wing. This is all 

 strikingly coleopteran, but the resemblance is to the higher 

 beetles, not to the lower ones in which the parapterum is free 

 from the episternum. This consideration somewhat invali- 

 dates any phylogenetic considerations. A trochantin is present 

 giving a ventral articulation to the coxa, an orthopteran char- 

 acter. The accessory plate e has already been mentioned and 

 simply connects the second parapterum with the head of the 

 wing. 



SUMMARY. 



The distribution amongst the three orders of the characters 

 discussed may be shown by the following tabulation : 



Orthoptera. 



Microthorax generally 

 well developed 



Labium attached to 

 microthorax or to 

 gular membrane. . . 



Gular sclerite absent. 



Prothoracic pleura re- 

 duced or rudimen- 

 tary 



Mesothoracic pleura 

 similar to the meta- 

 thoracic pleura 



Mesothoracic and 

 metathoracic pleur- 

 ites oblique 



Katopleure generally 

 present 



Trochantin generally 

 present 



First and second par- 

 aptera usually pres- 

 ent in both meso- 

 thorax and meta- 



EUPLEXOPTERA. 



microthorax well de- 

 veloped 



labium attached to 

 head 



first microthoracic 

 sternal plate has 

 gular position 



prothoracic pleura not 

 reduced 



mesothoracic pleura 

 similar to the pro- 

 thoracic pleura 



mesothoracic pleur- 

 ites oblique, meta- 

 thoracic horizontal. 



katopleure present in 

 mesothorax 



trochantin present. . . . 



paraptera absent in 

 mesothorax ; both 

 present in meta- 

 thorax, the first 



COLEOPTERA. 



microthorax rudimen- 

 tary or absent. 



labium attached to 

 head. 



gular sclerite present, 

 closing head behind 

 labium. 



prothoracic pleura not 

 reduced. 



mesothoracic pleura 

 resembling the pro- 

 thoracic more than 

 they do the meta- 

 thoracic pleura. 



mesothoracic pleurites 

 oblique, metathor- 

 acic horizontal. 



katopleure absent. 



trochantin present in 

 prothorax and 



mesothorax. 



paraptera rudimentary 

 or absent in meso- 

 thorax; the second 

 absent in meta- 



