NEARCTIC COLLEMBOLA, OR SPRINGTAILS, OF 

 THE FAMILY ISOTOMIDAE 



By J. W. FoLsoM^ 



INTRODUCTION 



Though all the known Nearctic species of Collembola of the 

 family Isotomidae are considered in this paper, our fauna undoubtedly 

 contains many additional ones. Of the 66 species and 16 varieties 

 herein treated, 28 species and 2 varieties are described as new. Of 

 the Nearctic forms, 21 species and 9 varieties are also Palearctic in 

 distribution. Specimens of most of the Nearctic species have been 

 compared with Palearctic specimens, not only by me but also by my 

 European colleagues, with whom I have been exchanging material 

 for more than 30 years. 



I have studied nearly all the type specimens of Isotomidae described 

 from North America, notably those of Packard, MacGillivray, and 

 Guthrie. 



When living in Cambridge, Mass., I made descriptions and draw- 

 ings from the Packard collection of Collembola in the Museum of 

 Comparative Zoology, through the courtesy of Samuel Henshaw. 

 This collection consisted mostly of the material described by Packard 

 (1873) in his "Essex County" paper. This paper had no illustra- 

 tions, but in the course of its preparation Dr. Packard made a great 

 many pencil drawings, which he gave to me, and these have been a 

 useful aid to the recognition of the species that Packard described. 



*Dr. JtrsTUS Watson Folsom, the author of this bulletin, died at Vicksburg, 

 Miss., on September 24, 1936, at the age of 65, shortly after the manuscript was 

 sent to the printer. A native of Massachusetts, Dr. Folsom was an entomologist 

 of wide training and experience. Since 1925 he had been associated with the 

 United States Department of Agriculture as entomologist, prior to which he taught 

 entomology at the University of Illinois for nearly a quarter of a century. At the 

 time of his death he was stationed at the Cotton Insect Laboratory of the Bureau 

 of Entomology and Plant Quarantine at Tallulah, La. Though accomplished in 

 many branches of entomological science, including anatomy and ecology as well 

 as taxonomy, Dr. Folsom became a world-famous authority on the orders Thy- 

 sanura and Collembola and published many papers dealing with these primitive 

 insects. The present monograph, on the Isotomidae, is one of the most exhaustive 

 studies of any group of Collembola ever undertaken and serves as a fitting climax 

 to the author's long career as a biologist. — Editor. 



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