NO. 8 



INSECT ABDOMEN SNODGRASS 



angular plate (in) lying mesad of the valvifer, which is fused with 

 the lower anterior angle (m) of the ninth tergum (IXT). A thick 

 bundle of short muscle fibers (Jf) extends from the inner face of the 

 first valvifer to the mesal plate (m) of the base of the first valvula. 

 The other muscles of the first valvifer are inserted on the dorsal 

 apodeme (e). They include a lateral muscle (C, i) from the seventh 



FiG- 33- — Structural details of ovipositor and muscles of first valvifer of 

 Magicicada scptendecim. 



A, left first valvifer and base of first valvula, external view. 



B, right first valvifer and base of valvula, mesal view, showing connections 

 with ninth tergum. 



C, base of ovipositor and adjoining segmental plates, with seventh tergum 

 removed to show muscles attached on apodeme (c) of first valvifer. 



a, articulation of first valvifer with ninth tergum; c, attachment of first valvula 

 to first valvifer; c, apodeme of first valvifer; m, mesal plate of base of first 

 valvula; n, anterior ventral part of ninth tergum attached to mesal plate (;«) 

 of first valvula. 



sternum {VI IS), and two dorsal muscles (2, 5) from the eighth 

 tergum {VI I IT). 



The second valvifer (fig. 31 B, 2Vlf) is an elongate plate, or 

 rather, a fold with a sclerotic outer wall, lying beneath and mostly 

 overlapped by the lower edge of the ninth tergum (A). From its 

 anterior end a slender apodeme (B, g) projects dorsally into the body 

 cavity for the attachment of muscles ; at its posterior end arises the 

 third valvula {3VI). The second valvula {2VI) is directly continu- 



