59 
The specimen illustrated has its columella area partly 
choked. Тһе caliee of another and larger example, though 
broken down at its margin, is clearer, and the description 
given is derived principally from it. 
Height, 10 mm.; diameters of calice, 11 mm. and 9 
mm. The larger example mentioned, though slightly re- 
duced by wear, is still 14 mm. high. 
Locality, ete.—Rare in the Eocene outcrop just below 
Rivernook House, Princetown. I name the species after 
the late Mr. Wilkinson, who discovered the section, and 
noted it as No. 7 on his map of the Cape Otway coast (1865). 
GENUS LEPTOCYATHUS. 
Leptocyathus ? convexus, spec. nor. Pl. xxiii., figs. За, b. 
The corallum is free, of compact appearance, almost crown- 
Shaped, but longer than broad, and slightly compressed ın- 
feriorly. The base is flat, elliptical, and without trace of 
adherence. 
The coste аге subequal, finely serrate on their edges, 
Separated by narrow grooves, and in six systems with four 
Cycles, of which the last is complete in two systems only, 
each of the remainder having this undeveloped in one half- 
System. From the base to the middle of the wall they are 
very broad, and then diminish gradually as they ascend. 
For about three-fourths of the circumference of the corallum 
all the coste. reach the base, but on one side the higher or- 
ders exceptionally join the tertiaries midway on the wall. 
The calice is convex and elliptical, with its axes in the 
ratio of 100 to 86. The septa are highly exsert, and in 
reality merely arched continuations of the coste, without 
defined boundary. Like the latter, they have dentate 
edges, but their sides are more strongly granular. They 
taper off towards the centre of the calice, and present the 
Same arrangement of cycles and systems as the coste. The 
principal septa are unequal, and the higher orders shorter 
and usually thinner; the latter are free superiorly, but fuse 
with the tertiaries just below the surface. The central 
fossa is small, excavated, and approximately circular. Its 
contour in the type calice is rendered somewhat irregular by 
an accidental fracture of some septa in two of the systems. 
lt contains a number of small papilli soldered inferiorly to 
each other. Some of these represent the columella, while 
the outermost of them are probably the pali. In another 
very young specimen there are six elongated pali and a small 
nodular columella. There is no epitheca, and the wall is 
apparently formed by the coste, which ultimately fuse 
together on the base. 
