Unionicola (Downesatax) alpa Cook, 1986 new comb.

Unionicola (Pentatax) alpa Cook, 1986: 160 .

Unionicola (Smithatax) alpa Vidrine 1992: 463; 1996: 40; Harvey 1998: 143.

Material examined. Northern Territory: 1 female, stream upstream of Wangi Falls, Litchfield NP, 13° 0 9.832 S 130° 41.166 E, 25 September 2005; 1 female, Gubarra Creek, upstream of pools, Kakadu NP, 12° 49.605 S 132° 52.708 E, 27 September 2005; 4 females, Manton Dam, 12° 51.726 S 131° 0 7.148 E, 1 August 1994; 2 females, Edith River, downstream of plunge pool, Nitmiluk NP, 14° 10.885 S 132° 11. 271 E, 2 October 2005.

Remarks. Previously only known from the type locality in Queensland, and reported here for the first time from the Northern Territory.