NORTH AMERICAN COLLEMBOLOUS INSECTS OF THE 

 SUBFAMILIES ACHORUTINAE, NEANURINAE, AND 

 PODURINAE. 



By Justus W. Folsom, 



Of the University of Illinois , Urbana, Illinois. 



The present paper treats of all the known species of North Amer- 

 ican Poduridae, with the exception of the subfamily Onychim'inae. 



Special acknowledgment is due to Dr. A. D. MacGillivray, of the 

 University of Illinois, from whom I have received large collections 

 of notable importance. 



Through the courtesy of Prof. Henry F. Nachtrieb, of the Uni- 

 versity of Minnesota, I have obtained for study many of the species 

 described by Guthrie. 



From Mrs. F. L. Harvey, of Orono, Maine, I acquired the large 

 collection made by Professor Harvey. 



Through the kindness of Mr. Samuel Henshaw I was enabled 

 some years ago to study all of Packard's material in the Museum of 

 Comparative Zoology. 



Cotypes have been deposited in the United States National 

 Museum, Washington, District of Columbia, and in the Museum of 

 Comparative Zoology, Cambridge, Massachusetts. 



Synopsis of Subfamilies, 

 collembola. 



Body elongate; Begmentation evident; the nine body segments being distinct as a 

 rule; the exceptions applying only to the last two or three abdominal segments. 



Suborder ARTHROPLEONA Borner. 



Body segments essentially similar; prothorax similar to the other segments and with 

 setae dorsally; never reduced or naked; postantennal organ usually present; 

 antennae short, four-segmented; mouth parts mandibulate or piercing-suctorial; 

 unguiculus frequently absent; furcula present or absent; when present, clearly 

 appended to the fourth abdominal segment; anal spines often present; integu- 

 ment tuberculate, not thickened in the form of sclerites; scales absent. 



Family PODURIDAE Lubbock, Borner. 



Proceedings U. S. National Museum, Vol. 50— No. 2134. 



477 



