Oribatei 393 



31. Genital plates with six pairs of setae; anterior pair of circumanal 

 setae laterad of anal plates Galumnidae 



Genital plates with five pairs of setae; anterior pair of circumanal 

 setae anterior to anal plate Parakalummidae 



32. Hysterosoma not segmented ' 33 

 Hysterosoma segmented . Protoplophoridae 



33. Genital and anal openings lying in large plate and separated from 

 each other Mesoplophoridae 



Genital and anal openings not lying in large plate and touching 

 each other Phthiracaridae 



Palaeacaridae Grandjean, 1932 



Figures 312-315 



Diagnosis: These mites have a very thin cuticle without special 

 sclerotization. Their body is divided into a propodosoma and a hys- 

 terosoma with a neck-shaped constriction between both. The propo- 



Figtme 312 Grandjeanacarus araneola " Figure 313 Acaronychus trdgardhi 

 Grandjean. Dorsum of female. Grandjean. Dorsum of female. (After 



(After Grandjean 1932) Grandjean 1932) 



dosoma has five pairs of setae (the rostral, lamellar, interlamellar, exo- 

 stigmatic, and angular setae). Pseudostigmatic organs are filiform or 

 lanceolate and are inserted into simple, cuplike pseudostigmata. The 

 chelicerae are large, uncovered, project far in front of the rostral plate, 

 and have dentate chelae adapted for chewing vegetable substances. 



