Horrox.—ÓOn new Tertiary Shells. 831 
anterior further apart. Anterior dorsal margin very short; the posterior 
dorsal margin slightly concave. Anterior end flatly rounded. Ventral 
margin flatly rounded. Posterior end rounded. 
Length, 2°75 inch ; height, 2:0 inch. 
Locality. Oamaru and Broken River. 
The type is in the Otago University Museum, from Oamaru. It was 
presented by Mr. J. Ashcroft, but the exact locality is not known. 
Mactra lavata. 
Shell oval, thin, inequilateral, smooth, rather compressed. Dorsal 
slopes nearly straight, the posterior much longer. Ventral margin rounded. 
Posterior end tapering, but not truncated nor angled. The whole shell with 
very fine concentric lines which are seen, under a lens, to be crossed by 
excessively minute radiating lines, giving a delicate granulated appearance. 
Right valve with two strong anterior and two equally strong posterior lateral 
teeth ; short and high, the inner on both sides being higher than the outer. 
Left valve with one lateral on each side; longer than those of the right 
valve. i 
Length, :9 inch ; height, *75 inch ; thickness, *42 inch. 
Locality. Petane. Collected by Mr. A. Hamilton. 
Loripes laminata. 
Shell small, orbieular, the umbo turned forwards, compressed, finely 
distantly laminated and radiately striated between the lamelle. Dorsal 
anterior margin hollowed ; the posterior dorsal margin slightly convex ; the 
ventral margin rounded. Anterior muscular impression elongated. 
Length, :28 inch ; height, :27 inch. 
Locality. White Rock River. 
Differs from L. concinna in the greater distance of the lamelle and in 
the radiate striation. 
Macrodon (Cucullaria) australis. 
Right valve. Shell transversely sub-oval, inequilateral, moderately in- 
flated, radiately finely ribbed, the ribs apparently scaly. There are about 
60 of these ribs near the margin, but many die out towards the umbo. 
Margin of shell crenated; the posterior margin perpendicular to the hinge 
line. Umbos rather anterior, incurved, slightly separated. Hinge area 
narrow, crossed obliquely by one anterior and one posterior line radiating 
from the umbo. Hinge line very slightly curved; two or three small teeth 
below the umbo, in front of which are four and behind it five teeth, all 
of which are nearly parallel to the hinge line; making about 12 teeth in 
Length, ‘5 inch ; height *4 inch. 
Locality, White Rock River and Mount Horrible. 
