164 
The Ohio Naturalist. 
[Vol. VII, No. 8 , 
find it most practical. As it grows colder in the fall the insects 
decrease in numbers. However, I have taken P. unicolor as late 
as December 13th in a comparatively open area, and after con¬ 
siderable cold weather and two or three snows. I do not doubt 
that they could be taken throughout the winter in the more pro¬ 
tected places. 
These insects are quite gregarious in their habits, and usually 
associate in colonies of from four or five to a dozen or more. 
They are very well protected by their color, which is usually 
of a reddish tinge in correspondence to the brown decaying 
wood on which they are usually found. 
Life History. 
So far as is known the eggs of Pcipirius have never as yet been 
observed, with the exception of P. pint Folsom. In connection 
with this I would note an experience in an attempt to solve the 
problem. Late in the fall some large forms of Papirius were 
placed in a vial containing damp decaying wood, and watched 
very closely. In about two weeks two colonies of young ones 
were observed, but in the meantime there had been no trace’ of 
any eggs, which might easily lead one to believe the eggs are very 
minute in some species. 
In appearance these young are lighter in color than the adults 
having more of a blue tinge than the brownish-purple adults. 
All their organs were perfectly formed, the antennae, however, 
being somewhat longer in proportion to the body than in the 
adult. Apparently these young are quite as active as their 
parents in their movements. With each successive moult they 
grow darker and take on more the color of the adult. 
Bibliography. 
1821. Say, Thomas. —Journal of the Academy of Natural 
Science of Philadelphia. Vol. 2. In a paper entitled, “Descrip¬ 
tion of the Thysanura of the United States.” (Read Nov. 21, 
1820). Say describes but one species of Papirius under the name 
of Smynthurus guttatus .Pg. 13. 
1859. Le Conte, John L.—The complete writings of Thom¬ 
as Say on the Entomology of North America. Vol. 2. A re¬ 
print of Say’s work. Smynthurus guttatus .Pg. S. 
1862. Fitch, Asa. —Eighth Report on Noxious and Other 
Insects of New York. The description of several Thyranura 
including Smynthurus novoeboraccnsis .Pg. 674. 
1873. Packard, A. S.—Report of the Peabody Academy of 
Arts and Science. In the appendix to the director’s report under 
the title, “ Svnopsis of the Thysanura of Essex County of Mass., 
with description of a few extratimital Forms.” Packard reviews 
the literature on American species and mentions the following 
