1 64 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 Papirius 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 

 vScience 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 Sniynthunts 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. 8. 



1862. Fitch, Asa. — Eighth Report on Noxious and Other 

 Insects of New York. The description of several Thyranura 

 including Smynthurus novoeboracoisis Pg. ()74. 



1873. Packard, A. S. — Report of the Peabody Academy of 

 Arts and Science. In the appendix to the director's report under 

 the title, "Synopsis 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 



