UNRECORDED GENERA OF THE OLDER TERTIARY FAUNA. 179 
arched stria which are more distant than the revolving lines. 
Length 17, breadth 5 mm. 
Locality:—Older Pliocene: Dry Creek bore, near Adelaide. 
Genus Ataxocerithium, nov. 
Type :—Cerithium serotinum, A. Adams in Sowerby’s Thes. Conch. 
sp. 48. f. 102 ; id Reeve, Icon. Conch. f. 146. 
Etymology :—Ataxos out of order, and Cerithium. 
Shell like Cerithium. Columella lamellar and elevated, con- 
tiguous with the outer lip and forming a tubular canal of moderate 
length, shortly but abruptly bent to the left and backward at the 
tip. The peristome is almost complete posteriorly. There are 
no varices and there is no posterior canal. The outer lip is 
expanded anteriorly and laterally projecting as in Certzthidea, 
behind which the whorl is peculiarly contracted. 
The aperture suggests Terebralia, e.g. T. sulcata, but its tubular 
canal is formed by the extension of the basal lip on to the colu- 
mella; it has also varices, at any rate there is a large variceal 
thickening at the posterior-third of the body-whorl against which 
the recurved basal margin is fused. The resemblance is greater 
in the young, or even better with Campanile, the sudden twist in. 
the columella simulates a plica at its base. It has some analogy 
with Vertagus, but the absence of a posterior canal and varix on 
last whorl forbid its association therewith. It differs from Colina 
by the short reverted canal, complete peritreme, and the absence 
of a variceal dilatation of the outer lip. The pullus is globulose © 
of one-and-half turns, with a bulbous free tip. 
ATAXOCERITHIUM CONCATENATUM, spec. nov., Pl. xi., fig. 6. 
Shell triangular-oval, spire somewhat acuminate of seven flat 
whorls separated by a deeply furrowed suture ; apex apiculate of 
about three small rounded whorls, ornamented with arched trans- 
verse threads, tip a little excentric. Spire-whorls ornamented 
with oblique, broad, flatly-rounded, transverse ribs (about twenty- 
four on penultimate whorl), and about five similar but narrower 
lirae, the intersections of which produce oblong pits. Last whorl 
