A Kevi?]w of the Laxd Moi^lusca of Western Australia. 
00 
The type has the spire depressed, the shell rtiscoidal, the umbilicus very 
wide and open, the mouth circular, lip a little rellected; the apex is granosely 
radiate, the radial sculi ture developing- into ribs, the grains continuing as a 
.subordinate feature. The south-western species, represented by olifjopleura, 
have the apex smooth, siiire elevated, shell subdiscoidal, sometimes sub- 
globose, the mouth circular, with the lijis continuous, the umbilicus narrow. 
The sculpture is similar but coarser, and this series is separated as a new 
subgenus, Angasietta. 
The Gantheaume Hay specie.s, P. ahstaiiHj however, has the apex coarsely 
granular, spire elevated, the umbilicus moderately wide, the mouth circular, 
lip.s continuous, expanded rather broadly and constricted behind, and is 
therefore snbg'enerically differentiated as Gantomia nov. 
Pleuroxia polypleura Tate 1899. 
Plate III., fig. 27. 
1899 — Angasella politplciira Tate, Trans. Roy. Soc. South Austr., Vol. 
XXII 1., p. 246, pi. VI., figs. 2a-c, Doe. Bunda Plateau, Great Aus- 
tralian Bight, South Australia. 
1879 — Helix eyrtophura Tate, Trans. Proc. Phil. Soc. Adelaide, South 
Austr., 1878-9, |). 120, not of Pfeiffer, 1862. 
1895 — Ilelii- tyvlopleutut Tledley, Proc. Malac. Soc. (Bond.), Yol. I., p. 260, 
July, not of Pfeiffei', Journ. de Conch., ^'ol. X., p. 227, pi. X., fig. 
4, July 1, 1862. 
Shell subde])ressed, flattened, Avidely umbilicate, with about sixty sig- 
moid threadlike ribs, the inter.sjiaces coarsely granular, the apex large and 
smooth, breadth 18 mm., height 10.5 mm. Specimens from the road between 
Madura and Muiidrabilla agree in size and sculplure and one is here figured. 
The umbilicu,s is better described as narrow and open, not much more than 
one-fifth the width of the base, while the large open .subcircular mouth has 
the thin lip reflected, and the lips are connected by a strong body callu.s. 
Shells collected at XeAvman Rocks are similar in sha]H‘ and sculpture but 
much smaller with the umbilicus a little wider, the granulation finer. The 
largest measures 13.5 mm. in lireadth and 8 mm. in height, and is subspeci- 
fically named Pleuroxia polypleura elflna nov. 
Pleuroxia commenta sp. nov. 
Plato HI., fig. 20. 
Specimens collected by Mr. Charh's Barrett, the tamed Victorian natural- 
ist and writer, on the Nullnrbor Plains were recorded as P. polypleura. Bet- 
ter knowledge allows their descrii)tion as distinct, and the exact locality 
proves to be Hamilton Tablelands, inside the West Australian boundary. 
Shell small, subde])ressed, spire a little elevated, sutures impressed, 
whorls rounded, last Avhovl flattened above and tlien rounded, a little descend- 
ing in front, mouth large, subeircular, outer lip a little rcdlectod, umbilicus 
narrow, deep, open. The eoloration of the living shells is a dirty broA\mish 
Avhite. Very similar in general appearance and size to P.p. elfina, but a 
little more depressed, and Avith mueli coarser sculpture. The ribs are much 
stronger, more distant, and the granulation almost obsolete, the ribs num- 
bering forty to forty-five. The mouth and umbilical features are very simi- 
lar to those of the jireceding. The shell measures 13 mm. in breadth by 7 
mm. in height. 
