146 



CLASS INSECTA. 



small grains. Their feet have only four distinct articulations. 

 The tail is soft, flexible, and composed of a lower piece, 

 mobile at the base, at the extremity of which two stems are 

 articulated, susceptible of approximation, separation, or 

 crossings, and which constitute the teeth of the fork. These 

 insects can erect their tail, push it with force against the 

 plane of their position, as if they let go a spring, and thus 

 elevate themselves into the air, and leap in the same manner 

 that fleas do, but to a less height. They usually fall down 

 on their backs, the tail being extended behind. The middle 

 of their belly presents a raised portion, which is oval, and 

 divided by a fissure. 



Some remain on trees, on plants, under the bark, or under 

 stones ; others on the surface of dormant waters, and some- 

 times even on the snow during the thaw. Many unite in 

 numerous societies on the ground, or on sandy paths, and 

 resemble at a distance a small heap of gunpowder. The 

 multiplication of some species appears to take place in 

 winter. 



The PoDURA proper (Podura, Lat.), 

 have the antennae of the same thickness, and without rings or 

 small articulations at the final piece. Their body is almost 

 linear or cylindrical, with the trunk distinctly articulated, 

 and the abdomen narrow and oblong.* 



Smynthurus, Latreille, 

 have the antennae more slender towards their extremity, and 

 terminated by an annulated piece, or composed of small arti« 



* Podura Arborea, Lin.; De Geer. Insect VII ii. 1 — 7. ; P. Alvalis, 

 Lin. De G. ibid. 8—10. ; P. Aquaiica, Lin. De G. ibid. ii. IV.; P. Plum- 

 bea, Lin. De Geer, ibid. iii. 1—4.; P. Ambulam, Lin De G. ibid. 5, 6; 

 P. Aquatica Grisea, De G. ibid. ii. 18, 21. 



The Podurae vaga, villosa, cincfa, annulata, pusilla,Ugnorum,fimetaria of 

 Fabricius. 



