NO. 1687. THE THORAX OF INJECTS— SXODORASS. 579 



cutum internal Mac Leay (1830). Internal part of antedorsum of 

 Amans (1885). Proterophragma in mesothorax, deutophmgma in 

 metathorax, Voss (1005). Prophragma in mesothorax, mesophragma 

 in some cases in metathorax, Berlese (1906). 



Prescutum {Psc). — The first subdivision of the notum. Not 

 homologous in all orders. Pra'scutum x\.ndouin (1824), Mac Leay 

 (1830), Newport (1839), Kolbe (1889), Voss (1905), Crampton 

 (1909). Exposed part of prophragma Kirby and Spence (182G). 

 Exposed part of antedorsum Amans (1885). Protergite Berlese 

 (190G). 



Presternum (Ps). — The anterior division of the sternum. Some- 

 times it is a transverse plate, but it is frequently reduced to two small 

 sclerites lying before the sternum proper or at the anterior angles 

 of it. Prwsternum Mac Leay (1830), Comstock and Kochi (1902). 

 Antesternum Amans (1885). Vorplatte Verhoeff (1903). Coxos- 

 temum Borner (1904), Voss (1905). Acrosternlte Berlese (190G). 

 Accessory sternal plates Snodgrass (1908). Prcesternum and Sternal 

 laterale Crampton (1909). 



Pronator disk (PD). — The large disk often carried internally by 

 one of the episternal paraptera for the insertion of the pronator 

 muscle. In a few cases it is attached to the adjacent part of the 

 episternum. Cupule du muscle pectorali-axillaire Chabrier (1820). 

 Grand cupule de Vaile Straus-Diirckheim (1828). Grand cupule 

 (of pronator apparatus) Amans (1885). Cupula also processo 

 pleurale (the second a mistaken identification with pleural arm) 

 Berles (1906). 



Pronator muscle. — The large muscle inserted upon the pronator 

 disk of the preparaptera. Muscle pectorale-axillaire Chabrier (1820). 



Prothorax {Pro.). — The first segment of the thorax back of the 

 microthoracic or neck segment. Prothorax Chabrier (1820), Au- 

 douin (1824). Manitruncus Kirby and Spence (1826). Corselet 

 Straus-Diirckheim ( 1828) . 



Pseudonotum (PN). — The postnotum, or second tergal plate of 

 the meso- and metathorax of nearly all adult insects except the 

 Orthoptera, the notum constituting the first or wing-bearing plate of 

 the tergum. The pseudonotum is a secondary plate, being absent in 

 all nymphs and in the pupte of Neuroptera and Coleoptera at least. 

 Best developed in the higher orders and nearly always connected 

 laterally with the epimera. It carries the postphragma. Cloison 

 costale or simply costal Chabrier (1820). Postscutellum Audouin 

 (1824), Newport (1839), Kolbe (1889), Crampton (1909). Post- 

 frmnum (?) in metathorax, Kirby and Spence (1826). Tergum in 

 metathorax, Straus-Diirckheim (1828). Suhpostdorsiim, including 

 postphragma, Amans (1885). Metaphragma, including true post- 

 phragma, Kolbe (1889). Pseudonotum (in Dermaptera) Verhoeff 



