i6o The Ohio Naturalist. [Vol. VII, No. 8, 



work on our American Papirius. While the genus is of very 

 little economical importance, yet it holds a unique position with 

 respect to the other Thysanura, and to the insects in general. • 

 It is the intention to use this paper as a foundation for future 

 work along systematic and phylogenetic lines. 



j Characters of the Genus. 



The characters which separate our apterous, or primitive 

 wingless insects, into the principal groups or sub-groups are, as 

 a rule, fairly well defined. The first attempt at classifying our 

 apterous fauna was made by Linnaeus in 1746, when he placed all 

 the springtails (Collembola) in the genus Podvira. 



In 1796 these were combined bv Latreille with the genus 

 Lepisnia and elevated to the rank of an order under the name 

 Thysanura. He distinguished two genera of the Lepismidae 

 and two of Poduridae, separating out the globular shaped species 

 under the name Smynthnrus. This teiin is now used to distin- 

 guish the family whose characteristics may be defined as follows: 

 Body globular, slightly longer than broad; the saltatorial organ 

 present, attached to the penultimxate abdominal segment; and 

 provided with a ventral sucker. 



This family, Smynthuridae , varies considerably from all the 

 other groups of apterous insects in having a round, almost globu- 

 lar body. The antennae are very much knobbed, and consist 

 of four segments, with the exception of the genus desci-ibed by 

 Bourlet, which he termed Dicyrtoma, having eight jointed an- 

 tennae. However, some doubt the validity of this genus since 

 the characters are very doubtful as the knobbed, four jointed 

 antennae of Papirius might easily be mistaken for an eight- 

 jointed one, nevertheless this genus will here be retained. 



The family, SmynthMridae , is divided into three genera which 

 are very closely allied and separated entirely on antennal char- 

 acters as follows: 



A. Terminal segment of antennae short, with whorls of haris. 



Papirius. 

 AA. Terminal segment of antennae long, annulated. 



B. Antennae with eight segments, abdomen with two tubercles. 



Dicyrtoma. 

 EB. Anter.nae with four segments, abdomen without tubercles. 



Sinynthnrus. 



The genus Papirius is distinguished by only one character, 

 that of having a short terminal segment to the antennae with 

 whorls of hairs, and being considerably annulated. The genus 

 was proposed by Lubbock in 1S72, having Pod lira jusca Geoffrey, 

 as its type, and characterized by Lubbock as follows: "Body globu- 

 lar, antennae four-jointed, terminal segment short with whorls 

 of hairs. Saltatory appendage comopsed of a basal portion and 

 two arms." 



