Millepora and Stromatopora. 309 
and Solander (p. 142) to be ‘‘ like so many beads of a neck- 
lace,” and that the structure is radiated, we probably should 
find these “ beads’? not only very much like Millepora globu- 
laris, but, in their hemispherical condition, diminutive forms 
of Stromatopora, saving the stellate arrangement of the cceno- 
sarcal venation. . 
Millepora globularis and M. Woodwardii appear to be 
closely allied in structure; but as yet I have only been able to 
see the septa (tabule) in the tubular spaces of the latter, and 
this in only one instance (fig. 9); so it is either uncommon 
or difficult to recognize. 
There is yet another form in the British Museum, about the 
same size as Millepora Woodwardit, which was free. It was 
irregularly elliptical (having been now cut in two), com- 
pressed, and seems to have been globular at first, subsequently 
overlapped by an additional growth, which causes one side to 
appear under the form of four triangular segments, crucially 
arranged, with their points in the centre, two of the segments 
opposite, being the overlapping parts of the last growth. 
But the structure otherwise is the same as that of all the 
rest, viz. radiating tubular spaces, increased in number by - 
branching towards the circumference, where their apertures, 
therefore, are of unequal size and at slightly variable dis- 
{ances apart, situated in the midst of the peculiar ccenosarcal 
skeletal tissue above described. ‘The specimen also presents 
four or more cylindrical excavations on its surface of different 
depths, one of which reaches nearly to the centre of the 
fossil. 
Thus the forms of this organism may be still more nume- 
rous, and, after all, like those of Millepora alcicornis, only 
various growths of the same structure ; hence the necessity 
of a review of all the species of D’Orbigny’s Coscinopore and 
the like, with which they seem to have been more or less 
identified, that they may be respectively relegated to their 
proper position in the animal kingdom. 
Postscript, Feb. 7, 1878. 
Since the above was written I have received from Dr. 
Steinmann (on the 4th inst.) a copy of his interesting paper, 
entitled ‘“ Ueber fossile Hydrozoen,” published in the ‘ Pa- 
leontographica,’ n. F. v. 3 (xxv.), p. 101, in which are 
enumerated all the species allied to Hydractinia, both living 
and fossil, that have been identified, adding to the latter 
three new ones, viz. Spheractinia diceratina, Ellipsactinia 
ellipsoidea, and Cylindrohyphasma Milaschewitschi, besides 
changing the generic names of Millepora globularis, Phillips, 
