30 Prof. P. M. Duncan on the 
lamine, which terminate either in synapticule, or in hooked 
processes with or without endothecal ends. The costae are 
short, subequal or very unequal, having some granulation 
and a greater or less development of endotheca. Synap- 
ticule very numerous between the septa near the base, less so 
higher up; they occur between the coste also. Another form 
shows the bifurcation of coste and their union also. The 
height is §°5 millim. and breadth 12°5 millim. 
One specimen of P. mamilliformis deviates from the type 
in being comparatively taller, having a distinct, low, incurved 
art above the attached base and ending superiorly ina ridge- 
shaped calicular margin, and in having a very convex calice. 
The gradations of form and structure from the low and broad 
types to this high one with such a well-defined convex calice 
are fairly well seen in the collection. The height of the 
corallum is 9 millim., of the calice 6 millim., and the greatest 
breadth is 12 millim. Some orders of the sixth cycle of septa 
are present ; there is no sunken central fossula, and the epi- 
theca is granular. 
Podoseris mamilliformis, Dune., requires some modifica- 
tion of its original definition, and the following is the correct 
specific diagnosis :— 
The corallum is simple, attached by a more or less circular 
flat, or concave base, being very low or slightly raised between 
the base and the calicular margin, constricted or not, 
and with coste. The calice is circular in marginal out- 
line, slightly or considerably convex, with or without a 
central fossula. The septa are numerous and become so 
early in lite, are unequal, many long and some uniting 
and reaching the columella or the fossula, some slender and 
many rudimentary: longer ones, straight or wavy, ornamented 
at the arched free upper edge with a single row of large 
granules. Columella small, mostly formed by the septal 
ends, and there may be some interseptal structures there, 
at the base of the fossula, with large granules upon it, or 
projecting without a fossula. ‘The coste usually more nume- 
rous than the septa, straight or wavy, uniting and bifurcating, 
ending in septal lamine, unequal or alternately very large 
and small, with granules. ‘The septo-costal number is from 
less than complete five cycles to five cycles with part of a 
sixth. Synapticule moderate in number, continuous with a 
series of ridges placed obliquely upon the flanks of the septa ; 
but the ridges may be curved, so as to resemble hooked pro- 
cesses in section, and may be free at one end or terminate in 
a thin endothecal process. Endotheca scanty, may exist 
