349 



Abdomen without wings; integument often rough or sculp- 

 tured and sometimes very little chitinized; legs fre- 

 quently stout or moniliform Nothrid^e. 



The three families of the superfamily Oribatoidea we 

 divide into 29 genera, which are distributed as follows: Ori- 

 batidce, 5 genera; Nothridce, 21 genera; and Hoplodermidce, 3 

 genera. 



KEY TO THE GENERA OF ORIBATIDjE. 



1. Superior bristles of body spatulate; mandibles long and 



slender; integument sometimes rough or pitted. . Pelops. 

 Superior bristles never spatulate; integument smooth. .. 2. 



2. Tarsi of first pair of legs broad at the tip; pteromorphae at- 



tached to the sides of the cephalothorax as well as to the 



abdomen Gymnobates. 



Tarsi of first pair of legs tapering at the tip; pteromorphae 

 attached to the abdomen only 3. 



3. Claws of the tarsi tridactyle 4. 



Claws of tarsi monodactyle Oribatodes. 



4. Lamella? large, attached to the cephalothorax by their 



posterior margins only Oribatella . 



Lamellae moderate, attached to the cephalothorax by their 

 inner margins Oribata. 



key to the genera of nothridce. 



1. Mandibles rod-like, serrate Serrarius. 



Mandibles chelate 2. 



2. Last pair of legs distant from the others and saltato- 



rial Zetorchestes. 



Last pair not distant from the others, nor saltatorial, being 

 used for crawling 3. 



3. Abdomen apparently divided into three parts by a pair of 



oblique sutures passing backward from the posterior 

 edge of the cephalothorax to the middle of the lateral 



margins of the abdomen Trizetes. 



Abdomen without such oblique sutures 4. 



4. Integument thin and little chitinized; variously colored . . 19. 



