CENSUS OF THE OLDER TERTIARY FAUNA OF AUSTRALIA. 407 
the following genera :—Actgon (this name takes the place of 
Tornatella), six spp. ; Semiacte@on, one sp.; Triploca, one sp. ; 
Tornatina, three spp.; Volvutella, Newton, 1891, instead of 
Volvula, H. Adams, 1850 (non. O’Ken., 1815), two spp. ; Sca- 
phander, one sp.; Bullinella, Newton, 1891, instead of Cylichna, 
Loven, 1846 (non. Burmuster, 1844), ten spp.; Ro«ania, four spp.; 
Cylichnella, one sp.; Ringicula, three spp.; and Umbrella, one sp. 
(Harris employs Umbraculum, Schumacher, 1817, as antecedent 
to Umbrella of Lamarck. 
Order NucLEOBRANCHIATA. 
Genus Atlanta. 
The only fossil examples of this Order so far known to me from 
book-knowledge are :—Oarinaria, three species, Miocene and 
Pliocene of Italy, and Eo-atlanta spiruloides, Lamarck (Cyclo- 
stoma), Eocene of Paris. The extreme delicacy of the tests of 
these gasteropods renders their preservation in a fossil state a 
matter of extreme improbability. The above-named species are 
founded on the shell, and it is of interest to be able to record a 
member of the Order in the form of an operculum in the Vic- 
torian Eocene. 
ATLANTA FOSSILIS, spec. nov. (Plate 19, fig. 7.) 
Operculum irregularly trapezoidal, nearly flat, but slightly 
elevated at the two ends; nucleus nearly marginal and apical, 
hemisphaeric of one and a half smooth turns; the expanded 
surface smooth and shining, but covered with broadish concentric 
folds. Under-surface with a broad thickened margin extending 
nearly the whole length of the left side, around the apical margin 
and half-way down the right side ; there is an umbonal depression 
corresponding with the nuclear elevation. Length 7°5 mm. 
Eocene, Cape Otway, Victoria (one example). 
Class PTeEROPODA. 
Genus Carolina. 
