PRELIMINARY CLASSiriCATION OF SCOLYTOIDEA. 



189 



ment of the primary and accessory muscles for the retractile move- 

 ments of the tube {a and h). 



The muscles (e) are more or less complicated and variable in size, 

 number, and attachments. In some cases, as in Dendroctonus, the 



Fig. 108. — Scolytus rugulosus: Posterior elements of 

 male reproductive organs. /, lateral aspect of 

 body; //, lateral aspect of body and accessories 

 in situ; HI, body accessories separated. See ter- 

 minology, Division 1, pp. 192-193. (Original.) 



Fig. 109. — Scolytus quadris- 

 pinosus: Posterior ele- 

 ments of male reproduc- 

 tive organs, lateral aspect. 

 Seeterminology, Division 

 l,pp. 192-193. (Original.) 



extensor and retractile muscles are prominent, the former (el) at- 

 tached posteriorly to the anterior edge of element c, while the sup- 

 plementary muscles (eS) are attached anteriorly to the posterior edge 

 of c and posteriorly to the inner surface of the eighth sternite, as in 

 Dendroctonus, or to the anterior section of element c and the eighth 

 59026°— 15 3 



