THYSANOURA. 
355 
FAMILY II. 
PODURELLAD, Lat. 
Antennae quadri-articulated; no distinct or salient palpi ; abdomen 
terminated by a forked tail folded under the venter when at rest, and 
used for leaping. The Podurellae form but one genus in the Lin- 
naean system. 
PoDURA, Lin. 
These Insects are very small, soft and elongated, with an oval head 
and two eyes, each composed of eight granules. Their legs have but 
four distinct joints. The tail is soft, flexible, and formed of an 
inferior piece, moveable at base, to the extremity of which are 
articulated two appendages susceptible of being approximated, sepa- 
rated, or crossed — they are the teeth of the fork. They have the 
faculty of elevating their tail, and then forcing it suddenly against 
the plane of position, as if they let go a spring, thus I’aising them- 
selves into the air, and even leaping like the Polices but to a less 
height. They usually fall cn their back, with their tail extended 
posteriorly. The middle of the venter exhibits a raised oval portion 
divided by a slit. 
Some keep on trees and plants, under old pieces of bark, or stones ; 
others on the surface of stagnant waters, and sometimes on that of 
snow during a thaw. Several unite in numerous societies on the 
ground, and at a distance resemble little heaps of gunpowder. Some 
species appear to propagate in winter. 
PODURA, Lat. 
Antennae equal, and without annuli or little joints to the last seg- 
ment ; body nearly linear or cylindrical ; trunk distinctly articulated ; 
abdomen narrow and oblong *. 
Smynthurus, Lat. 
Antennae slenderer near the extremity, and terminated by an 
annulated piece, or composed of little joints; trunk and abdomen 
united in a globular or oval mass f . 
* Podura arborea, L. ; De Geer, Insect. VII, ii, 1 — 7 ; — P. nivalis, L. ; De Geer, 
Ib., 8 — 10 ; — P. aquafica, L. ; De Geer, Ib., ii, 17 ; — P. plumbea, L. ; De Geer, 
Ib., iii, 1 — 4 ; — P, ambulans, L. ; De Geer, Ib., 5 — 6 ; — P. aquatica grisea, De Geer, 
Ib., ii, 18, 21. 
The Pod. vaga, villosa, clncta, anmdata, pusilla, Kgnorum, fimetaria, Fab. 
t Podura atra, L. ; De Geer, Ib., iii, 7 — 14 ; the Pod. viridis, polppoda, minuta, 
aud signata, Fab. 
