136 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



the wing leg muscles and their dorsal attachment marks the 

 dorsal limit of alar area (.4 .A.) and the ventral limit of scutum. 

 This alar area (so called because in abnormal larvae and also in 

 the pupa the wing evaginates from this region) is triangular 

 vith its apex pointing downward nearly bisecting the pleurum 

 (P). The sutures defining this apex are indicated by oblique 

 muscles (tp-pn l 2 ) one set extending forward to the posterior 

 notch of the inferior cunea the other backward to a corresponding 

 point behind. The anterior band (tp-pn 1 } evidently is the ab- 

 dominal muscles, tp-pn. The posterior cannot be compared 

 with any abdominal set in the cerambycids but occur in other 

 forms. This v-shaped suture below the alar area is considered 

 the tergopleural (t.p) suture. The thoracic pleurum is usually 

 divided into an anterior and posterior part by an oblique suture 

 p.s. which is considered the pleural suture. It extends downward 

 from the alar area and upward from the coxal lobe. It is much 

 more prominent in some other larvae. The sternopleural suture 

 retains its same relative position as in the abdomen. It is de- 

 fined by two muscles from near its middle, one set s-sp already 

 described, the other sc-sp, extends dorsad to the scutum repre- 

 senting abdominal muscle tp-sp. Thus the pleurum assumes a 

 more or less crescent shape having its anterior portion truncated 

 by the triangle bearing the spiracle while its posterior extends 

 far dorsad. Across the alar area extends a band of muscles a-a, 

 which may represent some modification of the abdominal band 

 d-s. 



In the Lepturinae and Priononae just in front and above the alar 

 area is a small triangular lobe. It is formed by the wide points 

 of attachments of the wing leg muscles and a shortening of some 

 of the muscles a -a from their anterior attachment on the superior 

 cunea. This (from its position) might belong to either alar 

 area or scutum but is regarded as a part of the latter. 



In the Cerambycinae it will be seen that the sternopleural 

 suture is not complete anteriorly but merges with that line 

 below it defining the posterior limit of presternum. Also the 

 muscle s-sp often moves down along this line. Thus pleurum 

 and presternum are not distinctly separated (a dotted line is 

 indicated between them) which condition will later be remarked 

 upon in discussing the prothorax. 



It will be noticed that in the Cerambycinae and Prioninae the 

 abdominal spiracle lies in an elliptical region the lower part of 

 which was before mentioned as part of the pleurum. Just in 

 front of this ellipsoid is the intersegmental skin (Is.S.). Also 

 in the abdomen one muscle (spi-pn) is attached to the spiracle 

 itself, and often extends to the parascutal line. Several others 

 (tp-pn) define the tergopleural suture just below it. Synchro- 



