122 
THE FRESHWATER MOLLUSCA OF VICTORIA 
running water. It is the commonest and most widely dis- 
tributed of the Victorian Planorhidae. It is subject to con- 
siderable variation, more particularly in the sharpness and 
position of the keel ; that these features are individual varia- 
tions I am convinced after examining thousands of specimens 
from all parts of the State. Three shells labelled Type in 
the National Museum collection, Reg. No. 36083-5, with 
locality Melbourne, appear under the name of Planorbis 
mccoyi Ten. Woods. I have failed to find any evidence that 
this name has been published. These specimens are insepa- 
rable from the species under discussion. Tenison Woods 
(Pr. Roy. Soc. Tas., 1879, p. 72) withdrew P. tasmanicus in 
favour of P. meridionalis Braz., under the impression that 
he had redescribed the same shell, an opinion not accepted by 
Petterd or May. Prom the original descriptions and figures 
provided by these authors, I am inclined to agree that 
tasmanicus and meridionalis are distinct species. 
Planorbis scottiana Johnston. 
(PI. Ill, Figs. 28, 28a, 28b). 
1879 Planorbis scottiana Johnston, Pr. Roy. Soc. Tas., for 1878, p. 26. 
1889 Id. Johnston, ibid, for 1888, p. 86, pi. 6, figs. 2a, b, c. 
1920 Id. May, Pr. Roy. Soc. Tas., p. 70, pi. 10, fig. 12 . 
1921 Id. May, Check-list Moll. Tas., p. 90, No. 884. 
1923 Id. May, 111. Index Tas. Shells, pi. 4i, fig. 18. 
Size of Type . — Greatest diam., 2 5 mm.; smallest diam., 
2 mm.; height, 0 5 mm. 
Locality . — Tarraville (T. Worcester). 
Vernacular Name. — Scott’s Flat-coil or Ram’s horn Pond- 
Snail. 
Observations . — A very minute, thin, pale, horny-coloured 
shell, somewhat flattened above and below ; finely transversely 
striated. It is the smallest representative of the genus in 
Victoria and is easily distinguished from our other species. 
Planorbis waterliousei Clessin. 
(PI. Ill, Figs. 29, 29a, 29b). 
1886 Planorbis waterliousei Clessin, Conch. Cab., i, Abth. 17, p. 188, pi. 
28, fig. 2. 
Size of Type. — Diameter, 4 5 mm., height, 0 7 mm. 
Locality . — Portland (W. H. Dillon). 
Vernacular Name. — ^Waterhouse’s Flat-coil or Ram’s- 
horn Pond-Snail. 
