Hydrachna palustris Smit, 1992

(Fig. 9)

Material examined. Queensland. 1/0/0, Catfish Waterhole, Lakefield NP, 15º 3’57.50” S 144º 17’8.43” E, 4-ix- 2000; 5/0/3, Hasties Swamp, Hasties Swamp NP, 16-ix-2000. Western Australia. 1/0/0, Pond Snake Creek, Millstream-Chichester NP, 21º 20’39.86” S 117º 14’30.34” E, 17-viii-1994.

Remarks. The species has a large elliptical gonopore, 110–116 long. Inside the gonopore two acetabula (?) are present, probably overlooked in the original description. These acetabula-like structures are also present in H. triscutata, and illustrated by Lundblad (1947) but not discussed.

The posteromedial extension of the fourth coxae of H. palustris is of variable width, from very narrow as illustrated in the original description (Smit 1992) till much broader. The species is known from two localities in Queensland among which the type locality (Hasties Swamp) and one locality in Western Australia.