THY8ANOURA. 355 



FAMILY II. 



PODURELKffi, 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- 

 neean 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 raising them- 

 selves into the air, and even leaping like the Pulices but to a less 

 height. They usually fall on 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 . 



* Podvra arborea, L. ; De Geer, Insect. VII, ii, 17 ; P. nirato, L. ; De Geer, 

 Ib., 810 ; P. aqvalica, L. ; DC Geer, Ib., ii, 1 7 ; P. pl*ml*a, L. ; De Geer, 

 Ib., iii, l l ; P. antoulaiw, L. ; De Geer, Ib., 5 6; P. aquatica grisea, De Geer, 

 Ib., ii, 18,21. 



The Pod. toga, ri//osa, CMcta, ajwuia/a, j**/Ja, lignorum, fimelaria, Fab. 



f Podura a/ro, L. ; De Geer, Ib., iii, 714 ; the Pod. riridw, polppoda, mwu/a, 

 and signata, Fab. 



