Hydrachnellae 



303 



Nautarachnidae Viets, 1935 



Figure 234 



Diagnosis: These mites have a strong 

 skin which has papillae. Lateral eyes 

 lie in capsules. The chelicerae are two- 

 segmented. The palpus has no peglike 

 processes and the palpal tibia lacks 

 sclerotized pegs distally. The coxal 

 plates lie in four groups of two each; 

 coxal plate iv has a posteriorly directed 

 process on the median posterior mar- 

 gin. The legs have swimming hairs. The 

 genital organ has two lateral, long, 

 many-suckered plates. 



Genus: 



Figure 234 Nautarachna crassa 

 (Koenike). Venter of female. 

 (After Viets 1936) 



Nautarachna Moniez, 1888 



Type. Nautarachna asperrimum Moniez, 1888 



Feltriidae Thor, 1929 



Figures 235-237 



Diagnosis: The body skin of these 

 mites is more or less plainly striated. In 

 the male there are no large, sclerotized 

 plates or shields while in the female 

 there are small, sclerotized plates or 

 shields. The coxal plates lie in four 

 groups of two each. In the male the 

 coxal plates are often very close to each 

 other; coxal plates iv are laterally broad- 

 ened and often lack a true medial mar- 

 gin; the posterior margin of coxal plate 

 IV is transverse. No swimming hairs are 

 present on the legs and tarsi in of the 

 male is usually sexually differentiated. 

 The genital organ is extensive or large, 

 with many small, porelike suckers; the 



Figure 235 Feltria zschokkei 

 Koenike. Venter of female. 

 (After Viets 1936) 



