CF 
narrow rim, is covered with a white, glistening epitheca. The 
surface is smooth, but lightly raised here and there in small, 
blister-like swellings. The costæ are stout and prominent on 
the basal margin of many examples, but in others the edges 
are merely crenulated by their equal projections. Except at 
the rim the cost are usually concealed on the base by the epi- 
theca, but occasionally they are faintly traceable beneath it, 
and in a single example show as well raised lines almost to the 
centre. At the margin they rise vertically to the height of 
the corallum, and then, bending sharply round, continue in 
the calice as septa. On the basal rim as well as on the peri- 
meter of the corallum they are rounded, very finely dentate at 
their free edges, and beset laterally by numerous sharply 
pointed granules. 
The calice is circular and flat. There are four cycles of 
septa and six systems, of which one is often incomplete. The 
primaries are free, and the remaining orders unite together in 
deltoid combinations. In a complete system each pair of 
quaternaries unites with the enclosed tertiary to form single 
septa of increased size. These, converging towards each 
other, meet in front of the straight secondary, and fuse with 
it. A short, stout septum is thus produced, which reaches 
the columella. In the type calice one system is incomplete, 
half of it being undeveloped. All the septa are more or less 
flattened at the surface, and are minutely granular on their 
sides. The columella is essential, of moderate size, and trabe- 
cular. Tt fuses with the edges of the primary and secondary 
septa. The margins of the septa are markedly coalescent over 
the apices of the deltas. The synapticule are few, and in 
many specimens scarcely noticeable. In the figured speci- 
men they are arranged in a concentric circle at about one- 
fourth from the margin. 
The coralla are from 3:5 mm. to 4 mm. in diameter, and 
from 1 mm. to 1:5 mm. in height. 
Locality, etc.—Abundant in the Miocene of the Grange 
Burn (upper Muddy Creek beds), and in the Oligocene of 
Beaumaris. The type is from the latter locality. 
Bathyactis excelsa, spec. nov. РІ. xxiv., figs. 4a, b. 
The corallum is discoid and lens-shaped. Its base is 
slightly concave or almost flat, and without trace of attach- 
ment. The coste are broad, equal, and continuous with the 
septa. They dentate the edge of the base by their projec- 
tions and remain prominent on its surface for a short dis- 
tance inwards, when they suddenly become much less distinct. 
Their surface and also the intercostal Spaces are covered with 
a fine granular epitheca. 
