By TOM IREDALE. 
51 . 
S.A. XAT.. 
VOL. XVIII. No. 
2 . 
“ing fairly rapidly. The mouth large, subcircular, open, lips 
slightly reflected, columella a little thickened and reflected over 
the very narrow umbilicus which appears as a chink only. Con- 
trasted with wilpenensis it is larger, the umbilicus Is differently 
formed, the mouth Is more open and the columella characters do 
not agree. On the other hand elderi develops a different shaped 
mouth, is banded, almost smooth, radials subdued, granules 
appearing and the umbilicus is smaller, the columellar reflection 
more developed, with the glaze extending boldly across the shell 
to suggest a continuous mouth. 
Type of mtisga measures: breadth 19 mm.; height 15 mm. 
Pleuroxia elderi. 
1892. Helix (Hadra) elderi Bednall, Trans. Roy. Soc. South 
Austr., Vol. XVI, p.64, pi. I, figs. 2 a-c, 4, 5, December. 
Birksgate Range, Central Australia. 
The “Horn” shells apparently included two species as they 
provide two different forms, one approaching musga closely, the 
other as described under that species. The figure indicates the 
latter as the typical form, and for this must be introduced a new 
subgeneric name, Fatulabia nov. the somewhat flaring aperture 
differing markedly from that of Pleuroxia. 
Pleuroxia hinsbyi. 
1916. Angasella hhisbyi Gude, Proc. Malac. Soc. (Lond.), \'ol. 
XII, p.42, fig. in text, March 20, ex Brazier MS. 
Mitchell District, Sllvertown, New South Wales. 
This locality is very close to the South Australian border, 
and this may prove only a variant of zvilpe7ie?isis. 
Genus Basedowena nov. 
Type B. cottoni nov. PI. II, fig. 24. 
A series from the Musgrave Ranges, collected by the late 
11. Basedow, one of South Australia’s best naturalists, as well as 
being otherwise very gifted, allows his memory to be memorial- 
ized as above. This constitutes one of the most distinct groups 
yet differentiated, apparently living alongside Pleuroxia and 
Sinumelon of two forms. 
Shell of medium size, subglobose, apex elevated, whorls 
straight sided, last whorl large, swollen, outer lip thin, the outer 
edges expanded, flaring; umbilicus narrow, hidden by strongly 
leflected columella which is triangular in shape. A glaze con- 
nects the reflection with the other lip whose descending edge 
almost frees the mouth from the last whorl. The pointed spire, 
the circular mouth with the expanded edge and the curious col- 
umellar reflection easily separate this from all other Xantho- 
melontid molluscs. 
