115 
thirds, when the more central ones divide into pairs up to the 
margin, the division line between each pair being faint. The 
coste visible superiorly correspond to the septa. The epitheca is 
rough, dense, and persistent ; it forms broad convex bands here 
and there on the surface. running parallel with the calicular 
margin, and most distinct in the interspaces of the coste. 
Height, including pedicel, 11 mm.; length of calice. 10-5 mm.; 
breadth of calice, 5°5 mm. All the examples found are practic- 
ally uniform in size. 
Locality.—Tolerably numerous in the Miocene beds of the 
Gippsland Lakes area. 
GENUS PLACOTROCHUS. 
Placotrochus ecornieulatus, spec. nov. PI. ii., figs. 3 a, D. 
The corallum is horn-shaped, smooth, and finely pedicellate. 
In young specimens there is a slight constriction just above the 
pedicel. The wall is thin at the summit, but becomes stouter 
inferiorly. The epitheca is strong, and is marked by transverse 
wavy ridges and lines, which are most numerous in the upper 
half of the coral, and reach the calicular margin. The calice is 
shallow and elliptical, but the relative lengths of the major and 
minor axes of the ellipse are not constant in the species. Thus 
in three examples measured the axes are respectively as 100 to 
64, 100 to 72, and 100 to 82. 
The septa are slightly exsert and most symmetrically disposed. 
They are in six systems, with four complete cycles; the primaries 
and secondaries are moderately stout and equal, the remaining 
orders becoming successively smaller. Though straight as regards 
their main direction, the septa are strongly waved and wrinkled, 
especially the primaries and secondaries for the inner two-thirds 
of their course. Perpendicular rows of moderate-sized, pointed 
granules are alternately placed on either side of the septa of the 
first and second orders, the summit of each successive fold carry- 
ing, as a rule, a single row of granules. Occasional granules also 
occur on the septa of higher order. 
The columella is a straight, thin, and short lamella with 
rounded margins, and projects distinctly from the bottom of the 
fossa. 
The costz correspond to the septa. The primary lateral costa 
on the convex curve of the corallum forms a strong well-marked 
ridge, which in some specimens is nodose. Other less prominent 
ridges mark the secondary and the remaining five primary coste. 
In the spaces between the ridges, which are barely concave, the 
tertiaries and quaternaries are indicated by faint lines. 
Height, 20 mm.; longer axis of calice (type), 9 mm.; shorter 
axis, 6° mm. . 
