A. C. OUDEMANS, NOTES ON ACARI. 61 



shining, without any wrinkles or shields; no vertical hairs; 

 mandibles chelate; maxillae with two-jointed palpi; legs 

 almost equal in size, short, 5-jointed; ambulacral caruncle 

 small, on long peduncles. No hypopi. Living under shield-lice 

 or cochineals. 



I wil try now to make keys of the Acaridae and its sub- 

 families, and I hope there will but little be changed in them 

 in future. I will admit that ray supposition about the presence 

 of vertical hairs be right; then we have the following key of 

 Acaridae. 



Acaridae. 



I With a pair of vertical hairs 2 



1. \ With only one median vertical hair VIII Eustathiinae- 



1 Without vertical hair . 7 



( Skin not wrinkled I. Tijroglyphinae 



\ Soft parts of skin wrinkled 3 



: Maxillae, or one or more pairs of legs difformed to hold 



3. \ a hair // Listrophorinae 



' Maxillae and legs normal, at least not difformed . 4 



j Body almost globular ; legs very short ; anterior dorsal 



I shield only ; burrowing cuniculi in birds and mammals 



4. I III Acarinae 

 I Body flat, short, or elongate; legs normal ; generally more 



than one dorsal shield ; not burrowing cuniculi . 5 



!Legs I and II not spinous 6 

 Legs 1 and II spinous VII Anahjinae 



i Epimera I in both sexes free . . IV Dermoglyphinae 



0. ', Epimera I in cT united to sternum; in j free V FalcuUgerhme 



■ Epimera I in both sexes united to sternum VI Siiringohiiyiae 



iSkin not wrinkled, smooth . XVIII Hemisarcocoptinae 

 Soft parts of skin wrinkled 8 



