LIBRARY

138 COLLEGE ENTOMOLOGY
long and the gut has three convolutions. The Malpighian tubules are arranged
in two large groups. There are 11 ganglia in the main chain. The young are
born alive.
Arixenia esau Jordan, the first species to be described (in 1909), was found
in the gular pouch of the large naked bat, Cheiromeles torquatus Horsfield, on
the Sunda Islands of the Malay Archipelago.
A rixenia jacobsoni Burr (1912) was collected in a bat cave near the seashore
at Babakan, Java. Concerning its occurrence there, Burr and Jordan (1913)
give the following very interesting statement: "The most conspicuous insects
inhabiting the cavern are, however, the earwigs mentioned above; they crawl
in countless numbers on the surface of the guano and everywhere on the rocky
walls. Evidently they live on the various larvee feeding on the guano, but besides
this they are constantly waging a terrible war against each other, the victors
devouring the bodies of their slain mates. Especially those which have
just moulted, their skins still being soft and of a yellowish-white color, are
hunted down by those in a more advanced state of maturity. . . .
"A more loathsome spectacle than these thousands of ugly, hairy creatures
running about hither and thither, fighting and devouring each other can hardly
be imagined."
Suborder FORFICULIN A Newman 1834:
For'fi-cu'li-na, from Latin jorfex, shears.
KEY TO FAMILIES I
1. Metapygidium and telson present as distind hardened plates; or else
they are lost in the pygidium when it is fused with the 10th tergite to
form a squamopygidium or anal process; pygidium without processes;
male genitalia double. . . . . 2
Metapygidium and telson degenerate; pygidium small but well developed,
often with processes; male genitalia single. . . . . 4
2. Squamopygidium rarely present; opisthomeres (pygidium, metapygidium,
and telson) distinct; body normally depressed; forceps rarely
sickle-shaped . . " 3
Squamopygidium always developed; body strongly depressed or flattened;
forceps sickle-shaped and without teeth . . . APACHYIDlE
3. Metapygidium and telson not reduced, but nearly as large as the pygidium;
femora compressed and keeled PYGIDICRANIDlE
Metapygidium and telson greatly reduced and much smaller than the
pygidiumi femora not compressed or keeled . . LABIDURIDlE
4. Second tarsal segment lobed or dilated ... 5
Second tarsal segment simple, neither lobed nor dilated . . LABIIDlE
5. Second tarsal segment with a narrow lobe extending beneath the third
CHELISOCHIDlE
Second tarsal segment lobed or dilated FORFICULIDlE
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p.143
1 There is much latitUde exercised by various authors regarding the classification of the true
earwigs. They.may be arranged in from three to 30 or more families which indicates the
present confusion concerning the group. '