58 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



THE DETERMINATION OF THE LINES AND AREAS ABOVE AND BELOW 



THE LATERAL ZONE 



Above the antipleural suture the segment is divided into the 

 following areas : 



Prescutum (prsc) , scutum (sc), scutellum (scl) , parascutum (pasc), 

 postscutellum (pscl), and the spiracular area (spa). 



The scutum and scutellum, which are sometimes hardly sepa- 

 rable, form the central dorsal part ; in front of these is the prescutum, 

 below and partly around them the parascutum, and behind them, 

 the postscutellum. Underneath those areas and limited on the 

 other side by the antipleural suture lies the spiracular area. 



All areas are denned by lines, fine wrinkles in the integument, 

 radiating from and determined by muscle attachments. In order 

 to make the figures as comprehensible as possible and in order 

 to avoid too many letters I have signified the muscle spot, its 

 radiating lines, and the area determined thereby, by the same 

 letter, and each muscle is then determined by the letters of the two 

 muscle spots between which it runs. The boundary line of scutum 

 and scutellum, I call the scutal line (sc). This is determined by a 

 muscle spot from which a long muscle (sc-pn) runs down to the 

 posterior cuneal notch. The transversal line separating scutum 

 and scutellum I call the scuto-scutellar line. The prescutum 

 is bounded by a line, the prescutal line (prsc), which runs from 

 the superior cuneal notch to the anterior margin of scutum. The 

 boundary line of parascutum, I call the parascutal line (pasc). 

 This is determined by a bundle of three muscles (pasc-pl), which 

 run down to the pleural suture (pi). The parascutum is divided 

 by a more or less curved line connecting the scutal and the para- 

 scutal line. I call this line the parascutal divisor (d). It is de- 

 termined by a flat muscle band (d-s), which runs backwards to 

 the superior cunea (s). This line is in reality a row of little dots 

 and varies considerably in size and position in the different types 

 of larvae; often it is also continued downward, below the parascutal 

 line. The postscutellum (pscl) is limited by the postscutellar 

 line, which runs behind the parascutum through the superior 

 attachment of the muscle (pscl-hypl), and terminates at the poste- 

 rior end of the antipleural suture. The spiracular area (spa), 

 is characterized by the presence of the spiracle and is limited above 

 by the parascutal line, below by the antipleural suture. 



AREAS BELOW THE LATERAL ZONE 



Below the pleural suture the segment is separated into the 

 following areas: the hypopleurite (hypl) immediately below the 

 pleural suture, the presternum (prst) and sternum (st), generally 



