138 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



From this modification and that in other larvae evidence is 

 suggested that the abdominal parascutum is in fact scutum 

 crossing the dorsal part of the segment, in the median dorsal 

 part of which a more or less rectangular plate, the scutal plate, 

 is often defined by muscles for mechanical purposes. This of 

 course would only be true in those forms where prescutum and 

 scutellum are absent or do not meet medianly. For when these 

 are developed as in the thorax of cerambycids and the abdomen of 

 clerids it more or less dorsally restricts the scutum, but still in 

 some forms is not entirely divided. It is believed that these 

 notal subdivisions in various larvae cannot be definately homo- 

 logized by the muscles and that the transition from the abdomen 

 to the thorax is brought about through different alterations in 

 different larvae. 



Just in front of the mesothoracic prescutum in Prioninae and 

 Cerambycinae is found a narrow transverse fold (Pn.F) extending 

 between the dorsal attachments of muscle s-sp. This fold is 

 considered intersegmental skin, and as it is of value in descrip- 

 tions is named the postnotal fold. 



Beneath the anterior extremity sternopleural suture will be 

 noticed a triangle with its apex extending ventrad. This is the 

 presternum (PrSt) homologous to that of the abdomen. It 

 sometimes fuses medianly or has a median portion. The suture 

 posteriorly limiting it is defined by three muscles (p-cx) to the 

 anterior dorsal point of coxal and by several muscles (?>?) extend- 

 ing backwards to the inferior cunea. Beneath the posterior 

 half of the sternopleural suture lies the postcoxal area, (PoCx) 

 surrounding the coxa. Its posterior ventral limit is weakly 

 defined in the Prioninae but strongly so in the Lepturinae. Just 

 in front of the coxa and behind the presternum the lateral ex- 

 tremity of the eusternum is constricted off in the Priorinat and 

 Lepturinae. This constriction is called the precoxal area (P.Cx). 

 In many larvae this area becomes strongly chitinized acting as 

 a brace in front of the coxa corresponding to the postcoxal area 

 behind. These two areas dorsally surround the coxa and in the 

 ceramlycids are usually fused and continuous but in many larvae 

 are distinct and divided by a strong chitinization (often internally 

 an appodeme). This fusion of the two areas is collectively called 

 the epicoxal area (PCx-\-PoCx). The coxa is defined by four 

 points, one dorsal more or less separating the precoxal and epi- 

 coxal areas, but having no muscle attachments, one posterior 

 dorsad, one anterior ventral and one anterior dorsad. The pos- 

 terior or often somewhat dorsal is defined by muscles, sc-cx, two 

 diverging bands to the scutal line, and one tp-cx to the tergo- 

 pleural suture. This point corresponds to that of the abdomen 

 made by muscle tp-pcx on the postcoxal line. The anterioi 



