ON THE TAXONOMY, BIOLOGY, AND DISTRIBUTION OF 

 THE BITING LICE OF THE FAMILY GYROPIDAE. 



By H. E. EwiNG, 



Of the Bureau of Entomology, United States Department of AyrkuUnre. 



INTRODUCTION. 



The family Gyropidae is a small family of biting lice that for 

 many years included but the single genus Gyro pus Nitzsch and its 

 two species, the two common biting lice of the guinea pig. Later 

 other species were added to this genus, and in 1910, Mjoberg, in his 

 extended studies on the Mallophaga and Anoplura, divided it, erect- 

 ing the new genus Gliricola for the slender species of the guinea pig. 

 Mjoberg was the first to give any good account of the mouth-parts 

 and certain important external characters of these lice, yet he made 

 no attempt to allocate the described species to the two genera, which 

 he recognized. 



In 1912 Neumann gave the first and, up to the present, the only 

 comprehensive account of the contained species. He recognized 

 the group as a whole as constituting only the single genus Gywpus 

 Nitzsch, Mjorberg's paper apparently being overlooked. Neumann 

 was the first to possess an abundance of material, and for this reason 

 his work is very valuable. He added five new species and one new 

 subspecies to the group and gave, among other things, a key to most 

 of the described species. 



Recently the present writer has had the opportunity of examin- 

 ing a large .collection of rodent and other mammal skins brought 

 fresh from South America by Dr. Alexander Wetmore, of the Bu- 

 reau of Biological Survey. These skins were taken during 1920 and 

 1921 in Argentina, Paraguay, and Uruguay. There were about 150 

 of them, and each had its accession number. Those that are men- 

 tioned in the present paper have been determined to genera for the 

 writer by A. H. Howell, of the Bureau of Biological Survey. From 

 the collections made from these fresh skins others were added from 

 old museum skins in the United States National Museum, which had 

 been previously determined to species. With this abundance of ma- 

 terial, to which should be added the specimens of the division of 



No. 2489— Proceedings U. S. National Museum. Vol. 63. Art. 20. 



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