Fe * eo A a ee 
v , ‘ A ‘ 7 
‘ 
¢ a 
188 RALPH TATE. 
where it has been collected by Messrs. G, B. Pritchard and Mulder, 
and by the former also at Muddy Creek near Hamilton. 
Shell oval-oblong 
g, slightly inequilateral, moderately ventricose, 
the post-dorsal margin rapidly sloping to the somewhat narrowed, 
compressed, and roundly truncated posterior margin. Medial 
portion ornamented with slender simple ribs, eighteen in number, 
inclusive of five or six smaller interposed ones, crossed by a few 
slight concentric folds and coincident flat threads. Antero- 
posterior diameter 46—ant. side 20, post. 26,—dorso-ventral 
diameter 35, thickness 31 mm. Proportions:—length 1, height 4, 
thickness $. 
Among Tertiary species, P. australica comes nearest to 
P. virgulosa, Sow., and it seems to differ from P. neozelanica 
in its flat concentric folds, less inequilateral, and its simple (not 
beaded) ribs. 
Genus Anatina. 
A. DOLABRAEFORMIS, spec. nov., Pl. xii, fig. 3. 
The discovery of a species of this genus in the Kocene at 
Belmont is due to Mr. Mulder of Geelong, who has been instrum- 
ental in adding largely to our knowledge of the Eocene fauna of 
that part of Victoria in which he resides. 
The species belongs to that section of the genus characterized 
by inequality of the valves, whilst its triangular-rotund shape and 
acute umbos separate it from all described species. The outline 
is rather equilaterally triangular, but shortly produced and trun- 
cated behind ; the anterior dorsal margin is very sloping, the post- 
dorsal is incurved in front of the umbos, but is otherwise nearly 
straight, then sharply bent at an oblique angle to form a flat 
broadish triangular post-dorsal area; the ventral margin is gently 
curved upwards to the acutely rounded anterior margin. The 
umbos are about central and acute. Antero-posterior diameter 
48 (less breadth of posterior area 38), ventro-dorsal diameter 36, 
sectional diameter 18. 
