Hydrachnellae 



299 



Tyrelliinae Koenike, 1910 



Genera: 



1. Tyrellia Koenike, 1895 



Type. Tyrellia circiilaris Koenike, 1895 



2. Neotyrellia Lundblad, 1938 



Type. Neotyrellia petricola Lundblad, 1938 



Hygrobatidae Koch, 1842 



Figure 229 



Diagnosis: As a rule the body of these 

 mites is weak-skinned. The palpal femur 

 often has processes on the inner side while 

 the anterior inner margin of the palpal 

 femur is often toothed. There are small 

 setae on the inner side of the palpal tibia, 

 and often a median, swordlike setae is 

 present. The coxal plates usually lie in 

 three groups (the coxal plates i are united 

 behind the maxillary organ); the plates 

 are seldom in four groups of two each or 

 all united with one another. Coxal plates 

 I, II, and III are usually narrow and elon- 

 gated, while plate iv is large. The suture 

 between plates in and iv usually does not 



reach the inner margin of the group. Usually the legs have no swimming 

 hairs and seldom do they have separate, long hairs. The genital organs 

 have plates and as a rule three pairs of suckers (they seldom have fewer 

 or more suckers). The male has a roundish plate with a more or less 

 splitlike sexual opening while the female has two (seldom four) sepa- 

 rate plates. 



Figure 229 Hygrobates ple- 

 hejus Lundblad. Venter of 

 male. (After Lundblad 1930) 



Hygrobatmae Claus, 1880 

 Genera and subgenera: 



1. Hygrobates Koch, 1837 



a. Hygrobates s. str. 



Type. Hydrachna longipalpis Hermann, 1804 



b. Capobates Jhor, 1898 



Type. Capobates sarsi Thor, 1898 



