CENSUS OF THE OLDER TERTIARY FAUNA OF AUSTRALIA. 395 
relatively short straight open canal. Columella with two oblique 
plaits just behind the origin of the snout. The sinus of the lip is 
broad and shallow ; the fascial band occupies the whole antesutural 
or post-carinal slope. Length 21, breadth 7 mm. 
Eocene, Cape Otway, Victoria. 
This species is distinguished from the foregoing by its stouter 
build, angulated and costated whorls, and by more pronounced 
spiral sculpture. 
Borsonta POLYCESTA, spec. nov. (Plate 19, fig. 2.) 
B. polycesta, Tate, ms., op. cit. 
Shell fusiform, aperture as long as the spire: spire-whorls 
costated and otherwise like B. Otwayensis, except that they are 
convex, the costations more nodulose and the body-whorl not so 
abruptly narrowed at the front. Length 13, breadth 4-5 mm. 
Eocene, Cape Otway, Victoria. 
BorsoNIA BALTEATA, spec. nov. (Plate 19, fig. 10.) 
Shell fusiform, aperture a little longer than the spire. Embryo 
globulose, rather large, smooth, of one and a-half turns. Spire- 
whorls four and a half, medially angulated, distinctly constricted 
in front of the anterior suture giving rise to the appearance of a 
harrow convex rib margining the suture. First two nobulose- 
costated smooth, the costz evanescent at the antesutural band ; 
gradually the backward extension of the cost become restricted 
to the anterior slope, and traversed by spiral threads, and the 
posterior slope by arcuate threadlets. Last whorl, the ornamen- 
tation consists (1) on the post carinal area, which is slightly con- 
cave, of arcuate threadlets, more or less duplicate on the sutural 
band, and anterior thereto by three or four spiral threads, and of 
(2) on the antecarinal area of a crenate-dentate keel, and about 
twenty spiral threads, the posterior four or five crossed by axial 
threads which produce slight nodulations at the intersections; the 
axial threads are continued to the front in much reduced strength; 
the spiral threads are crowded and weaker at the extreme front. 
