OF WASHINGTON, VOLUME XVIII, 1916 141 



showing the muscle attachments studied. Comparing such a 

 skin and a specimen with the muscles intact gives a correct in- 

 terpretation of their attachment and position. 



EXPLANATION OF PLATES. 



y 



These plates were drawn by Miss Mary Carmody from sketches by the 

 author. They are somewhat diagrammatic for the sake of clearness. In 

 no segment are all the muscles drawn but are placed in two segments to 

 avoid confusion. For the same reason several muscles are drawn with 

 angles. The lettering is not present on every muscle on every plate but 

 when not-present it can be easily located on another plate where lettered. 

 A few unimportant muscles are not shown in all the figures. 



Capital letters represent areas; small letters separated by a dash rep- 

 resent muscles, by a period lines or sutures. 



These figures were drawn from the internal right side of the larvae so 

 that looking at the lines they will represent the external left side and the 

 muscle can be imagined to be just beneath the skin on that side. 



Plate VI. Lepturinae larvae (principally from Leptura nitens). 



Plate Vll. Prioninae larvae (principally from Orthosoma). 



Plate VIII. Oerambycinae larvae (principally from Chum and Kin- 

 phidion). 



Plate IX. More important longitudinal muscles. 



LETTERING ON PLATES. 



IA first abdominal segment; HA second abdominal segment; IIIA- 

 third abdominal segment; A A alar area; a-a muscles across alar area 

 (thorax); a.sc line forming anterior boundary of scutum or scutal plate; 

 a. s.l. line forming anterior boundary of spiracular ellipse; a-sp muscle 

 from mesothoracic spiracle to the center of the prothoracic alar area; 

 c-l longitudinal muscles from cunea to collar of head; Cx coxa; d para- 

 scutal divisor line; d-s muscles from parascutal divisor to cunea behind; 

 e-c prothoracic muscles from eusternum to collar; e-x-i sternal thoracic 

 muscles from eusterno-sternellar line to cunea in front and behind; ESI 

 eusternum ; rxl.stl eusterno-sternellar line between eusternum and slerneU 

 him; i-esl muscles from centra! part of eusternum to cunea behind; 

 i-est.stl muscles from eusterno-sternellar line to inferior cunea behind; 

 i-rt inferior retractor muscle of the head; /.s-.S Intersegmental skin; 

 i-stl muscles from central part of sternellum to cunea in front; l-/>/,-* 

 longitudinal abdominal muscles from posterior notch to superior cunea 

 behind; MxTh Mesothorax; MtTh Metal In >ra\; P pleurum; PuS<- 

 parascutal area; ixt.xc parascutal line bounding this area below; pnxc-s/i 

 muscle from parascutal line to sternopleural suture, defining the ventral 

 limit of parascutiim and the dorsal of the spiracular area; /V.c precoxal 

 area; p.cjc postcoxal line; p-c.r the muscle from posterior margin of 

 prestermun to coxa; p-i muscles from posterior margin of prestermuu 



