216 
nOHN EXPEDITION—MOLLUSCA. 
t 
Sub-family PLANonniNiE. 
Genus Planorbis. 
Planorbis fragilis (Brazier), Smitli. (Plate XTX., Fi^. 23.) 
Reference—Proc. Linn. Soc., vol. xvi., 1882, t. 7, tigs. 1, 3, p. 294. 
Syn. — P. brnzieri^ Clessin, Conch. Cab., 2n(l ed.. Band i., p. IGG, t. 24, lig. 6, 
1886. 
Localities. —Dead sludls in the rejectamenta of the River Fiidce at Crown Point 
and Running Water; living in Palm Creek, oil' Glen Palms, and in the Hugh 
River at Stuart’s Pass. 
The shells of this species are more compressed and more acutely keeled 
than those of P. gi/berti, as stated in the original diagnosis. A moi-e valuable 
diagnostic character is atloi-ded by the position of the keel, and in conseipience the 
form of the aperture. In Ji gilberti the keel is central, and in fragilis it is far 
below the middle. Tn Figs. 22 and 23, PI. XIX., T have endeavoun'd to show 
these diflerences. 
Clessin, op. cif., has renamed P. pfogilis on the ground that Smith’s name is 
pre-occupied in the genus, whereas Dunker’s P. fragilis was not published till 1886, 
or four years after. 
Sub-family Ancylin^. 
Genus Ancylus. 
Ancylus australicus, Tate. 
Reference—Trans. Roy. Soc. S. Aust., vol. iii., p. 102, t. 4, f. 4, 1880; Smith, 
Proc. Linn. Soc., vol. xvi., t. 7, figs. 36, 37, 1882. 
I.ocalities. —Bagot’s Creek, Laurie’s Creek, Ollaroo Water-hole on the Darwent 
Rivei’, Arumbera Creek, and Palm Creek ; taken alive at all the stations. 
This species has a wide disti'ibution in the northern parts of the continent in 
Arnheiin Land and Noi th Queensland, in the central parts as above indicated, and 
in Cooper’s Cri'ek at Innamiidva, in the south about Adelaide and Melbourne. 
