93 



NOTES ON ACARI 



Eleventh Series ') 



(Classification, Parasitidae, Ixodidae, Thrombidiidae, 

 Labidostomidae, Acaridae) 



BY 



IX Dr. A. C. O Ü D E M A N S. 

 (With Plates 11—13.) 



1. Remarks on the relative ancienty and mutual relation 

 of the Families of Acari. 



Though several classifications have been proposed by several 

 authors, in none of them the author has attached importance to 

 the probable relative ancienty of the groups. In most instances 

 one single character was enough to divide the Acari — or a group 

 of them — in two smaller groups, e. g. the being provided with 



The Series are independant from one another, 



