396 ANNUAL, REPORT SMITHSONIAN INSTITUTION, I&IO. 
special set of large muscles attached to the front of the head. A 
sectional view of it is shown by figure 6. 
Insects that devour the leaves or any kind of solid food, as do grass- 
hoppers, beetles and caterpillars, have a pair of large strong jav/s for 
biting and chewing and a second pair of softer jaws with movable ap- 
pendages that serve a variety of purposes accessory to the first pair. 
Since the cicada and its relations, constituting the order of insects 
called Hemiptera, have no jaws like those of the biting insects, it has 
usually been assumed that the pair of setae on each side are their 
representatives and this appears to be confirmed by a study of their 
development. 
SONG. 
During the first two weeks of June the woods were full of the 
" locusts " and the noise of their singing. The song has no resem- 
blance whatever to the shrill, undulating screech of the annual 
locusts so common in August and September and known as the dog- 
day cicadas. The song and all the notes of the larger variety of the 
17-year cicada are characterized by a burr sound and at least four 
different utterances may be distinguished. First, there is the pro- 
longed burring sound of their ordinary song, the individual notes 
of which become lost in the continuous hum of the multitude, and I 
never heard one singing this song in solo. Next there is the so-called 
" Pharaoh " note, which requires some imagination to interpret it 
thus, for it is characterized by the same burr tone as the chorus song. 
The Pharaoh sound is usually sustained only about five seconds, 
when it terminates with an abrupt falling. Then it is repeated in- 
definitely at intervals of two to five seconds. When each note is 
begun the singer lifts his abdomen to a rigid, horizontal position, 
evidently thus opening the ventral drum chambers. As the sound 
ends the abdomen drops again to the usual somewhat sagging posi- 
tion, seemingly thus cutting off the sound by closing the drums; but, 
of course, the two are coincidental, since the sound terminates when 
the tympanal muscles cease to vibrate. 
The males are easily observed uttering the Pharaoh song as they 
sit in the bushes or on low branches of the trees, but the community 
singiqg is always done in the tops of the trees, where I never observed 
an individual musician at close range vrhile performing. 
Their third note is a soft purring sound of one syllable, which is 
often heard from those sitting low in the bushes. It is shorter than 
the Pharaoh sound and lacks the abrupt terminal drop. Finally, 
when a male appears to be surprised or frightened, he often, afe he 
darts av/ay, utters a loud, rough burr sound. They utter the same 
note when picked up or otherwise handled. This seems to be their 
