BRISTLE-TAILS AND SPRING-TAILS. 91 
it would be of great interest to ascertain their relation to the 
other remains. Let us trust that ere long there may again be a 
season in France when a thought may fairly be bestowed on other 
camps and other earthworks than those on which attention is now 
so unfortunately concentrated. 
BRISTLE-TAILS AND SPRING-TAILS. 
BY A. S. PACKARD, JR., M.D. 
Tue Thysanura, as the Poduras and their allies, the Lepismas, 
are called, have been generally neglected by entomologists, and 
but few naturalists have paid special attention to them. * Of all 
those microscopists who have examined Podura scales as test ob- 
jects, we wonder how many really know what a Podura is? 
In preparing the following account I have been under constant 
indebtedness to the admirable and exhaustive papers of Sir John 
Lubbock, in the London Linnean Transactions (vols. 23, 26 and 
27). Entomologists will be glad to learn that he is shortly going 
to press with a volume on the Poduras, which, in distinction from 
the Lepismas, to which he restricts the term Thysanura, he calls 
Collembola, in allusion to the sucker-like tubercle situated on the 
under side of the body, which no other insects are known to 
possess. 
The group of Bristle-tails, as we would dub the Lepismas in 
distinction from the Spring-tails, we will first consider. They are 
abundant in the Middle States under stones and leaves in for- 
ests, and northward are common in damp houses, while one beau- 
MR ee to re ee EET 
* Nicolet, in the “ Annales de la Societe Entomologique de France” (tome v, 1847), has 
given us the most comprehensive essay on the group, though Latreille had previously 
l 0 i edes Thysanoures ” in the 
is, 1832,” which I have not 
a useful account of them in the third volume of “ Ap- 
teres” of Roret’s Suite a Buffon, published in 1844. j j 
Abbe Bourlet, Templeton, Westwood, and Haliday have published important 
hys. ra d ei d Ol fers, a German 
anatomis rtant 
country Say and Fitch have described less than a dozen § 
described a new species of Campodea, while Humbert a 
entific ia 1 ; f Japvx (J. Saus ii) from Mexico 
\ 
