348 



ing for it the name Nothridce, derived from the genus Nothrus, 

 which name has been previously so applied by CI. Canestrini and 

 made a subfamily name by Mr. Michael. 



Having thus created three families out of the group to 

 which the old family name Oribatidce was given, we regard the 

 group as a superfamily, as suggested by Mr. Banks, including 

 in it, however, as already stated, three families for the two 

 I Oribatidce and Hoplodermidw) recognized by that author. The 

 following is a summary of the characters of the superfamily 

 Oribatoidea: 



Integument generally well chitinized, which gives the in- 

 dividuals a beetle-like appearance. Cephalothorax with a pair 

 of funnel-shaped or cylindrical structures on the dorsum which 

 are called pseudostigmata, from each of which projects an 

 elongate specialized organ, or seta, the pseudostigmatic organ; 

 chitinous blade-like expansions termed laraellse often present. 

 Palpi small, with five segments, generally hidden by the ros- 

 trum: mandibles chelate. Abdomen usually oval; ventral 

 surface covered by a large chitinous plate termed the ven- 

 tral plate; dorsal surface often with a large chitinous wing- 

 like expansion on each side, known as the pteromorpha. Legs 

 composed of five segments, the distal segment bearing a claw 

 (unguis) which is either monodactyle or tridactyle. 



KEY TO THE FAMILIES OF ORIBATOIDEA. 



1. Cephalothorax and abdomen immovably fused together; 



body never compressed; mouth-parts small; with trachea? 

 opening at the acetabula of the legs; legs often long or 



slender 2. 



Cephalothorax hinged to the abdomen and capable of being 

 folded down over the ventral surface of the same; body 

 compressed; mouth-parts large; without trachea?; legs 



Stout HOPLODERMID M. 



2. Abdomen possessing chitinous wings, or pteromorpha?.; integ- 



ument usually smooth and shiny and always well 

 chitinized; legs never stout or with swollen seg- 

 ments Oribatidce. 



