1972] 
Hlavac — Prothorax of Coleoptera 
127 
In addition, rim-fold joints between body wall sclerites and mov- 
ing parts are very widely distributed within the Coleoptera. 
Prothoracic configurations of extant forms can be derived from 
a single hypothetical stem form diagnosed as follows. 
HYPOTHETICAL stem configuration: Pleuron large, rigid, 
forming distinct part of body wall, with broad anterior and posterior 
flanges; attached by rim-fold joints to notum and sternum. Endo- 
pleuron present. Trochantin external, motile. A complete anterior 
collar and partial posterior collar enclose most of the intersegmental 
Figs. 6-9. Prothoraces of Polyphaga and Adephaga. 
Figs. 6, 7. Lateral external and internal views of Omalium marginatum 
(Polyphaga, Staphylinidae). [See text and captions of Figs. 25-55 for ex- 
planation of Fig. 6A, B]. 
Figs. 8, 9. Same of Amphizoa insolens (Adephaga, Amphizoidae). 
