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Article X. — The Orilxdoiih-d of IlHtidis. By Hkxry E. 

 EwiNG. 



Introduction. 



The inites of the group (hilHifoidcd. thoiigli ;il)nndaiit in 

 this country, have received Init little study. Ahout a hundred 

 specie.'! have heen recorded from America. Out of thi.s 

 number over 90 per cent, are new .species, yet with this very 

 large per cent, of new species only two new genera ( Gi/iinio- 

 hatt's Banks and Tamidalnis Ewing) are peculiar to our country. 

 Our fauna is especially rich in the abdominal-winged forms 

 { Ffn-o(/(isf('j'ea ). The nnnil)er of the Pfn-rnjusfcira described 

 from this country, up to the present, is over 40. Xearly all of 

 these winged forms have a sliiny integument, which fact may 

 have caused their more ready discovery and the apparently 

 much greater percentage of winged forms here than in Europe. 



The Oriliitioiih'rt are appropriately called beetle-mites be- 

 cause of their hard, chitinized integument. They are ((uite 

 distinct however from the mites of those groups which are para- 

 sites or pseudoparasites of beetles, and which for this reason have 

 been called beetle-mites by some persons. The internal anatomy 

 and life history of this group have been studied very carefully 

 by A. D. Michael, of England, to whom the writer is indebted for a 

 large collection of named European species. The physiology 

 and embryology of the group are almost entirely unknown. 

 Economically the beetle-mites have no great importance. 



The writer is very much indel)ted to Dr. J. W. Folsom. of 

 the department of zoology of the University of Illinois, for 

 assistance in many ways. Mr. ,1. D. Hood, a specialist in the 

 study of the Tli;/.<in/opf('ni. has not only collected material for 

 the author from many parts of the state, luit has in most cases 

 furnished mounted specimens and also added notes ui)on their 



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