Tribe Conchostraca. 
Family Limnadiidae. 
Genus Limnadopsis SPENCER and HALL, 1896. 
The laterally very compressed bivalve shell ovate, in alkohol translucent and 
very thin. The union between the two halves of the shell extending along the whole 
length of the dorsal line, which is raised into a very compressed spined keel. Lines 
of growth forming clearly-marked, threadlike ridges. The intervals between the 
more recent lines of growth continued on the dorsal keel into backwardly-directed 
spines. These decreasing in size from behind forwards. Beaks well marked. First 
pair of antennae much smaller than the second one. Frontal appendages (haft- or 
affixing organ) are present. 
This genus is distinguished from HKstheria and Cyclestheria inter alia by the 
presence of a frontal appendage; from Limnadia, Fulimnadia and Paralimnadia, by 
the conspicuous lines of growth, by the longitudinal series of spiny processes on the 
dorsal edge of the shell, and by the great number (26—32) of pairs of feet; from 
Limnadia and Kulimnadia also by the different number of lines of growth. 
Limnadopsis birchii (BarrpD). 
Figures 1—4. 
Estheria birchii BairpD. Proc. Zool. Soc. London, 1860, p. 392, pl. LXXII., 
fig. I a—e. 
Limnadopsis squirer SPENCER and HaALL. Report Horn Expedition, II., p. 239, 
figs. 15—19. 
The species has been well described and figured by SPENCER and HALL. 
Habitat. 
This species which up to the present has been recorded from New South 
Wales, South Australia, or Central Australia was found by Dr. MJÖBERG in West 
Australia about 160 English miles from the coast in Mowla Downs Gilgally creek, 
close to the desert-rock in South Kimberley Yamusa District on the 25th November 
