207 
fossa become as large as those of the first cycle. Afterwards also 
the septa of the third cycle develop more strongly. The dorsal and 
ventral septum of the first cycle remain much smaller than the 
other ones. The final result is « corallum that possesses a row of 
strongly prominent septa belonging to the first, second, and third 
cycles at each side of the axial groove, whilst in the parts along 
the greater axis the septa are much less conspicuous. The central 
part of the septa of the higher cycles with which two septa of a 
next higher cycle have fused are very thin and but slightly lower 
than the septa of the lower cycles. In the younger specimens the 
costae extend in regular lines from the centre to the periphery; 
in older specimens the costae may assume a more or less winding 
course, whilst in the centre of the lower surface irregular figures 
may arise by the fusion of parts of neighbouring costae. 
The anthoblasts of this species (figs. 39 and 47) are always 
solitary, in most cases their stalk does not attain a greater height 
than 3 mm. In the smallest specimen found (diameter of the 
disc 4 . 5 x 4 mm) four complete cycles of septa have developed. 
Those of the first cycle are free, the septa of the third cycle are 
fused with the secondaries, the quaternaries with the tertiaries. 
The disc is slightly oblong, not hexagonal. The fifth cycle of septa 
appears when the dimensions of the disc amount to about 7.5X7 
mm. In the largest anthoblast the dimensions of the disc are 
11 X 10 mm. In this anthoblast five complete cycles of septa are 
present and some members of the sixth cycle. Usually the antho- 
cyaihi come free before this size is reached for I found many free 
anthocyathi of much smaller size between the stalked individuals. 
The scar of detachment is soon covered by living tissue and the 
Sharp outline of it vanishes in most cases very shortly after the 
anthocyathi have become free. This is already visible to a certain 
degree in the smallest anthocyathus found free, whose larger dia¬ 
meter is 6 mm. But in other specimens the scar remains much 
longer visible, even in some specimens exceeding 20 mm in length 
a definite scar is still to be seen. 
On several anlhocauli from which an anthocyathus has’ detached 
itself a new disc is developing. A ring-shaped wall (Semper’s 
Wachsthumsring) a little beneath this new disc indicates where the 
former anthocyathus has loosened itself from the stalk. 
