CENSUS OF THE OLDER TERTIARY FAUNA OF AUSTRALIA. 409 
Meretriz, Lamarck, 1799 (Cytherea, Lamarck, 1805). 
Sunetta, Link, 1807 (Meroe, Schumacher, 1817). 
Gari, Schumacher, 1817 (Psammobia, Lamarck, 1818). 
Hemimactra, Swainson, 1840. Example, Mactra howchiniana, 
Tate. 
Anapella, Dall, 1895 (Anapa, Gray, 1853, non Gray, 1847). 
Cuspidaria, Nardo, 1840 (Ne@ra, Gray, 1834, non Robineau- 
Desvoidy, 1830). 
Glycimeris, Lamarck, 1799 (Panopea, Menard de la Groye, 
807. 
Solenocurtus (emended from Solecurtus). 
Genus Martesia. 
Young shell like Barnea, the valves becoming closed anteriorly 
in the adult ; one large accessory valve. 
MARrTESIA ELEGANTULA, spec. nov. (Plate 20, figs. 7 a, .) 
Elongate-conoid, inflated and obtusely rounded in front, atten- 
uated behind ; valves closed in front (the gap of the young shell 
being arched over by a subcallous growth), slightly gaping behind. 
Exterior of each valve unequally divided into two dissimilar 
ornamented portions by a perpendicular furrow, extending from 
the umbo to the ventral margin ; the external furrow is reproduced 
internally as an obsolete rib. The anterior side is further divided 
into a trigonal area, occupying the extreme front, which is the 
Supplemental growth of the adult, this area is ornamented with 
fine strie of growth coincident with sinuate front margin of the 
adolescent shell ; and into a second larger and highly ornate area 
bounded posteriorly by the antemedian transverse furrow and 
anteriorly by the sutural line between the two growths. The 
ornamentation of the second area consists of regular sigmoid 
acute retroverted lamelle-like folds, coincident with the margin 
of the adolescent shell ; the superior margin of the lamellz closely 
crenulated, the crenulatures passing into granules; in addition 
there are about ten plicw radiating from the lunular area, rendered 
conspicuous by carrying small granulations in place of crenulatures 
at the intersections with the concentric folds. The part of the 
