ox A KEW CRUSTACEAN. 571 



40. Fauna of West Australia. — IV. Pahemonetes ausfralis, 

 sp. n., being the first record of the genus in Australia. 

 By W. J. Dakin, D.Sc, F.Z.S., Professor of Biology 

 in the University of W. Australia. 



[Received August 5, 1915 : Read November 9, 1915.] 

 (Plate I.*) 



Index. 

 Ststematic : Pa2;e 



Fal(emonefes austrnlis^ sp^ iii 571 



With the exception of the Phyllopoila and the crayfishes, few- 

 aquatic animals appear to have been collected and recorded from 

 the fresh waters of Western Australia. 



Among the so far unrecorded species is a prawn-like crustacean, 

 which is extremely common in many of the rivers near Perth. 

 What its actual range in the continent may be, remains to be 

 discovered. The species was first found by the aiithor in a tow- 

 net which had been thrown at random from a river-bank and 

 pulled back ; the net just scraped the bottom on the way. About 

 fifteen specimens were caught in this very short, careless haul, 

 and as the animals are pretty active in their movements they 

 must have been present in large numbers in the water. 



Since the first discovery, specimens have been obtained from 

 several other districts. All proved on investigation to belong to 

 the genus Pcdcemonetes. This new record marks a considerable 

 inci-ease in the known geographical range of this genus. So far 

 as I can determine, only one species of ralcemonetes is known to 

 occur in Europe, but that is found in Sweden, Denmark, Belgium, 

 France, Italy, Spain, and the Black Sea. It has also been collected 

 in the -British Islands and even so far south as Egypt. This 

 species, Palcemonetes varians, lives in water that is more or less ■ 

 brackish and close to the sea, as well as in the perfectly fresh 

 water of lakes and rivers. 



Most of the known species of the genus Palcemonetes appear 

 to be American — the following having being recorded. Palcemo- 

 netes vulgaris (sea-water — h&js and estuaries of U.S.A. coast), 

 Pcdcemonetes exilipes Stiinpson (fresh-water — U.S.A.), P. carolinus 

 Stimpson (marine — U.S.A. coast), P. argentinns Nobili (South 

 America), P. kadiakensis Rathbun (North America), P. calcis 

 Rathbun (blind species found in caves in Cuba), P. antroi^um 

 Benedict (blind species from an artesian well in Texas), P. eigen- 

 manni Hay (blind species from ca.ves in Cuba). The Rev. T. R. 

 R. Stebbing writes me that he has described and figured a species 



* For explanation of tho Plate s«e p. 574. 



