282 

 Genera: 



A carology 



1. Hydrodroma Koch, \%?>1 



Type. Hydrachna despiciens Miiller, 1776 (= Hydrodroma umbrata 

 Koch, 1837) 



2. 0;co/7A'/5 Nordenskiold, 1905 



Type. Oxopsis diplodontoides Nordenskiold, 1905 



Hydryphantidae Thor, 1900 



Figures 203, 204 



Diagnosis: The hydryphantids are red in color. Their skin has papil- 

 lae and may or may not have a frontal plate but is seldom well ar- 

 mored. A median eye is present only when the frontal plate is present. 

 The palpal tibia has a dorsal-distal process. The coxal plates are in 



Figure 203 Hydryphantes tenuabilis Figure 204 Hydryphantes ruber (De- 

 Marshall. Anterior portion of body Geer). Venter. (After Marshall 1944) 

 showing eyes and plate. (After Mar- 

 shall 1946) 



four groups. All legs have swimming hairs and the tarsal claws are 

 simple, sickle-like. The genital organ has two movable plates and 

 three or more pairs of genital suckers. 



Hydryphantinae Piersig, 1896 



Genera and subgenera: 



1. Hydryphantes Koch, 1841 



a. Hydryphantes s. str. 



Type. Acarus aquaticus ruber DeGeer, 1778 



b. Octohydryphantes\.ux\dh\2id, 1927 



Type. Hydryphantes octoporus Koenike, 1896 



