(de. a. c. oudemans). notes on acari. 101 



Genera 17 — 55, the Hygrobaiinae, may be divided in three tribus: 

 Hygrohatae (sensu novo), with the genera 32 — 55; Frontipodae 

 with the genera 19 — 31 ; and ArrJienurae with the genera 17 and 18. 

 Here follows a table, at the same time a «key» of the sub- 

 families and tribes of the Hydrarachnidae. ' 

 iEyes near together, joined by a 

 crista 2 



• Eyes far remote, no crista more. 3 



i Crista long, longitudinal ... I Limnocharhiae. 



' Crista short, transversal ... II Enlainae. 



I Penultimate joint of palps dorsally 

 and distally lengthened tooth-, 

 "^* - poniard-, or hook-like (claw-like) 4 

 Penultimate joint of palps not 



lengthened dorsally .... 5 



/ Mandibles of 2 joints ; last joint 



• claw-like Ill Hydryphantinae. 



' Mandibles of 1 joint, stylet-like . IV Hydrarachninae. 

 i Last joint of palps free ... V Hygrolafmae. 

 ^' Last joint of palps partly sunk in a 



' distal pit of penultimate joint. VI Piersigimae. 

 Groups of subfamily V Hygrobatinae : 



1 Palps usual 2 



Fifth joint ending in a claw, 

 which forms pincers with the 

 I distally lenthened flexible side 



( of the 4th joint 3 



( Coxae of 2 in 4 groups; in $ 

 \ often close together, rarely joined 



^- \ medianly A Hygrobatae. 



I Coxae of $ and Î forming one 



( plate B Frontipodae. 



3. Only one tribe C Arrhenurae. 



Classification of Halaciridae. The genera are not united in sub- 

 families. 



Classification of Nicoletiellidae. Ditto. 



