274 Acarology 



4. Limnohalacarinae Viets, 1927, is to be found in fresh water in 

 Europe, Africa, and North and South America. 



5. Simognathinae Viets, 1927, is marine and is to be found in the 

 Adriatic, North Sea, Irish Sea, Caribbean, and Pacific-Antarctic Ocean. 

 Predaceous forms are to be found in the Bay of Biscay and the weit- 

 em Indian Ocean. 



6. Enterohalacarinae Viets, 1938, is parasitic in the gut of echino- 

 derms, at least in the larval and nymphal stages, and is to be found in 

 the western Pacific Ocean. 



7. Halixodinae Viets, 1927, is parasitic, at least as nymphs, on gills 

 of Amphineura in New Zealand. 



8. Astacopsiphaginae Viets, 1931, is parasitic, at least as nymphs, 

 on gills of fresh water decapod Crustacea in Australia. 



9. Halacarinae Viets, 1927, is predaceous, principally marine, and 

 rarely fresh water, and is cosmopolitan in distribution. 



10. Porohalacarinae Viets, 1933, lives in fresh or brackish water, 

 and is probably cosmopolitan in distribution except in the Arctic and 

 Antarctic seas. 



Reference: 



Newell, Irwin M. 1947. A systematic and ecological study of the Hala- 

 caridae of eastern North America. Bull, of The Bingham Oceano- 

 graphic Collection, Peabody Museum of Natural History, Yale Univ. 

 10 (3): 1-232. 



Hydrovolziidae Thor, 1905 



« Figures 187, 188 



Diagnosis: Red watermites, the hydrovolziids measure from 0.80 to 

 0.95 mm. long. They have a small, predorsal shield and a large post- 

 dorsal shield. At the anterior, lateral margins of the postdorsal shield 

 is a pair of large, lateral shields and surrounding the postdorsal shield 

 is a series of small plates or shields. A double eye in a capsule is lo- 

 cated in a lateral indentation of the predorsal shield (eyes are lacking 

 in subterranean species). The coxae are divided into two distinct 

 groups; the legs are placed laterally so that coxae in and iv stand out 

 from the side of the body. There are no swimming hairs on the legs 

 and the tarsal claws are smooth and sickle-like. No genital suckers are 

 present. The palpi are five-segmented and simple with a clawlike end 

 segment, somewhat as in Cunaxidae. 



