
COTTON—SOME TERTIARY FossiL MOLLUuUscsS 665 
Victoria, under the name Chamosirea albida Lamarck, Recent, Tasmania (type), 
the Southern Australian living species, 
MYADORA ALEA sp. nov. 
Plate xx, figs, 20, 21, 22, 
Shell ovate, solid, anterior rounded, posterior truncate; right valye convex, 
overlapping the left all round ; concentrically sculptured with about thirty slightly 
irregular ribs about half the width of the interspaces; a ridge runs from the umbo 
to the postero-ventral margin, becoming less marked towards the margin; left 
valve flat, less strongly sculptured and smaller. Height 15 mm.; diameter 19 mm. 
Loe, : Salisbury Bore, 330 feet, holotype, Adelaidean, Tate Museum, 
Remarks: Somewhat like the Recent M. pervalida Cotton 1931 from South 
Australia, but less strongly sculptured, fewer concentric ribs and less tapered 
posteriorly and smaller. Myadora ovata Reeve from the Philippines is differently 
sculptured. 
GASTROPODA. 
SOPHISMALEPAS ACRA sp. Nov. 
Plate xx, figs. 4, 5. 
Shell thin, alongate-ovate, depressed ; sides a little convex converging towards 
the anterior end, so giving the shell a tapered effect; anterior sharply rounded, 
posterior more widely rounded; orifice almost central, large, one-quarter the 
length of the shell, narrowly oval; sculpture of numerous fine radials, threads 
crossed by slightly weaker concentric threads with occasional spiral accremental 
lamellae; interior smooth, margin of shell fattened, internal margin of orifice 
having a narrow calloused border. Height 3 mm., diameter 14 mm. and 9 mm. 
Loe. : Salisbury Bore, 330 feet, holotype, Adelaidean, Tate Museum. 
Remarks: This is a more delicate shell than the Recent 8. nigrita Sowerby 
1834, described from South Tasmania, and it is quite different in shape. 
TUGALIA NOTA sp. nov, 
Plate xxi, figs, 11, 12, 
Shell elongate ovate, elevated; protoconch sharp, at the posterior third; base 
arched, margin of shell crenulated within; front extremity sinuate, sculpture of 
numerous, fine radial riblets crossed by equally developed concentric riblets, the 
whole giving a close and regular fenestrate pattern ; interior smooth with a groove 
