LIMNZEID. 31 
Sub-Genus, Ameria—A dams. 
Whorls flattened and angulated or carinated at the posterior part. 
Spire short and depressed. 
Found in Australia and New Zealand only. 
P. variabilis, Gray; Dieff, New Zealand, ii., p. 248. Shell ovate, 
spire conical, apex often eroded, whorls ventricose, swollen, and often 
flattened and keeled behind. 
Length, 1% to 34 inch. 
The young shells have an acute spire. Very variable in shape. 
(Gray.) 
P. moesta, Adams; P.Z.S., 1861, p. 144; Reeve, Conch, Ic. f. 3 
Shell obliquely ovate, thin, olive- brown ; spire moderate ;_ whorls 5, 
carinated and flattened posteriorly ; ; aperture oval, columella plait 
distinct. 
Long., 7; diam, 5% lines. (Adams.) 
Found in all parts of New Zealand. 
Sowerby remarks that it ‘‘ has very close relations with P. tadbulata 
(Gould.) The chief difference consists in the rounded. angles of the 
whorls in the latter, and the distinct square angles in the former.” But 
he describes P. ¢abulata as remarkable for the flatness of the whorls 
above the angle. 
P. lirata, Woods; Pro. Tin. Soc. of N. S. Wales, iii., p. 138, 
plate 13, f- 6. Shell small, imperforate, elongately ovate, shining, sub- 
diaphanous, yellowish horn, covered more or less with a sooty perios- 
traca ; whorls 4, slopingly spirally and regularly punctately lirate (lire 
somewhat distant), carinate above, lines of growth close and very fine ; 
spire exsert, acute; aperture elliptic; peristome sharp, very thin; lip 
not reflected but twisted, exactly defined and anteriorly produced. 
eneth,, 336; (breadth, 2); aperture, length, |-25, breadth, 12); 
length of spire, ‘12 inch. (Woods.) 
Taieri River. 
Not so long nor so inflated as the last. (Woods.) 
The proportions given make this a longer shell than either the last 
Or the next s(. W..E1.) 
P. cumingii, Adams; P.ZS., 1861, p. 144. Shell ovate, thin, 
light-brown ; spire short; whorls 4, angulated and flattened at the 
posterior part ; aperture sub-ovate, peritreme continuous; columella 
plait moderate. 
Long, 8; daim., 54% line. (Adams.) 
N. Australia and New Zealand. (Cuming.) 
Sub-Family—Planorbine. 
Shell spiral, .discoidal or depressed, many whorled; aperture 
crescentic. 
Genus, PLANORBIS—-Guettard. 
Tentacles slender, filiform. Foot short, ovate. Shell dextral, 
discoidal ; spire depressed ; whorls numerous, visible on both sides ; 
