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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



ous with the anterior end of the second valvifer, there being no 

 movement between the two parts except such as is permitted by the 

 flexibility of the narrow base of the valvula. The inner surface 

 of the outer wall of the second valvifer bears a strong longitudinal 

 ridge near its dorsal margin (fig. 34, 2Vlf). At a point on this ridge 

 anterior to the middle of the valvifer is the articulation of the second 

 valvifer with a fulcral process {p) on the lower margin of the ninth 

 terguni near the anterior angle of the latter (fig. 33 B). Two large 

 antagonistic muscles (fig. 34, 6, 7), arising on the ninth tergum, 

 are inserted anteriorly and posteriorly on the second valvifer at op- 

 posite sides of the tergal fulcrum. Tergosternal muscles of the ninth 

 segment are absent in the cicada as in other Hemiptera. 



2Vlf 



Fig. 34. — Right half of ninth and post-genital segments of Magicicada sep- 

 tendecim, mesal view, together with second valvifer and its muscles. 



g, anterior apodeme of second valvifer ; p, fulcrum of second valvifer on ninth 

 tergum between insertions of anterior and posterior muscles {6, 7). . 



The muscles of the ovipositor, or associated with it, are the fol- 

 lowing : 



1. Depressor of the first valvifer (fig. 33 C). — A broad muscle 

 arising on lateral part of seventh sternum ; goes dorsally in mem- 

 branous fold laterad of the valvifer to dorsal apodeme {e) of the 

 latter. This muscle, as in Gryllus (figs. 17 A, 19 A, j), is an inter- 

 segmental ventral muscle of the seventh segment attached posteriorly, 

 not on the eighth sternum, but on the valvifer of the eighth segment. 



2. First levator of the first valvifer (fig. 33 C). — A long tergo- 

 pleural muscle of eighth segment, arising dorsally on anterior margin 

 of eighth tergum; inserted ventrally on dorsal apodeme of first val- 

 vifer. This muscle rotates the valvifer upward on its posterior articu- 

 lation with the ninth segment. 



