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A New Isopod from Central Australia belonging 

 TO the Phreatoicidae. 



By Charles Chilton, M.A., D.Sc, C.M.Z.S., 



Professor of Biology, Canterbury College, New Zealand. 



(Communicated by Professor F. Wood Jones). 

 [Read April 13, 1922.] 



In this paper I describe a new and most interesting 

 fresh -water Isopod kindly sent to me by Professor F. Wood 

 Jones, of Adelaide University. It -was collected in June, 

 1920, in artesian water from the Hergott (Marree) bore, in 

 Central Australia, a little south of Lake Eyre. 



The animal proves to belong to the Phreatoicidae and 

 comes sufficiently near the typical genus Plireatoicus to be 

 placed in it. The Phreatoicidae is a family of fresh-water 

 Isopods of which the first member was described in 1883, from 

 the underground waters of the Canterbury Plains in New 

 Zealand. Later on other species of the genus, and of closely 

 allied genera, were described from the surface and under- 

 ground waters of Australia, and, still more recently, Barnard 

 (1914, p. 231) recorded a species of Fhreatoicus from the 

 mountain streams of Cape Colony, South Africa, The family 

 is quite distinct from all the other families of the Isopoda, 

 and forms, by itself, the sub-order Phreatoicidae, marked by 

 some primitive characters and by a striking but superficial 

 resemblance to the Amphipoda. The characters and distri- 

 bution showed that the family must be an ancient one, and 

 in 1918 this was proved by the discovery of a fossil species 

 from the Triassic beds of New South Wales. The fossil form 

 is not very different from some of the existing species, and, 

 apparently, members of the family have been living in fresh 

 waters on some part of the Australian continent from Triassic 

 times up to the present. The discovery of another quite dis- 

 tinct species in Central Australia is most interesting and 

 important as confirming the conclusions already arrived at. 

 Further details of the history of the family will be found in 

 my paper describing the fossil species (Proc. Hoy. Soc. N.S. 

 Wales, vol. 51, p. 383). 



The mode of occurrence of the new species is worthy of 

 note. In his first letter. Professor Wood Jones said: — 

 "Hergott is a pure artesian bore; the water is hot, and the 

 creatures were in thousands swimming in the hot water near 

 the bore head." The specimens sent were found to possess 

 well-developed eyes and to be of a dark-slaty colour, so that 



