Millepora and Stromatopora. 307 
sonien””’ or Eocene as stated by mistake in my paper, ‘ An- 
nals,’ Uc. p. 67), be allied to Millepora Woodwardit? At all 
events the former brings down the stelliform systems of vena- 
tion seen in the Silurian Stromatopora &c. to the Chalk age, 
as indicated by the type specimen from the Trias, given by 
D’Orbigny (Cours élément. Paléont. et Géologie, vol. i. 
p- 411, fig. 407), of which a tracing will be found among the 
illustrations (fig. 10). 
Through the kindness of Mr. Woodward I have also been 
able to examine the little globular fossils generally, in the 
British Museum, which have been obtained from the chalk of 
Dover, when being washed and prepared for officinal purposes. 
These would appear to have been first called by Phillips 
Millepora globularis (‘ Geology of Yorkshire,’ 1829, vol. i. 
p- 234, tab. 1. fig. 12), and are identical in structure with 
Millepora Woodwardii, except that they have no stellate vena- 
tion or branched tubulation in relief on the surface. More- 
over they are frequently more or less perforated by a cylin- 
drical cavity filled with chalk, in which they are identical 
with some specimens of Parkeria, wherein the cavity appears, 
from its heterogeneous contents, to have been filled with 
‘“sea-bottom ”’ (p. 59, 7. c.); while, from the radiated structure 
in both Millepora globularis and Parkeria not having been 
altered or turned out of its course by the presence of the 
cavity, it would appear that the latter had been made by 
some organism after the Millepora or Parkeria had completed 
their growth respectively. At the same time, in Parkeria, a 
nucleus of this heterogeneous material frequently appears, 
singly or in plurality, in the midst of the structure, while 
some specimens of Millepora globularis present two or more 
such cavities of different depths, indicating that, if the exca- 
vating organism perished or left its cavity when the latter 
was shallow, and the Millepore or Parkeria continued to 
grow afterwards, the cavity might appear in the midst of the 
structure filled, as we see it in Parkeria, with “ sea-bottom.”’ 
Sometimes the excavation passes directly through both Jl- 
lepora globularis and Parkeria, simulating, as Mr. Woodward 
states, the beads of a “ prehistoric race ;” and sometimes, as 
just stated, there may be more than one excavation present. 
Frequently Millepora globularis, when fixed, assumed a 
hemispherical shape ; and also, having frequently grown as if 
on a conical body, the base presents a corresponding excava- 
tion, which is annulated concentrically with alternate grooves 
and elevations, covered with a smooth compact material, 
which contrasts strongly with the rough apertured surface of 
the hemispherical or free side, arising from the projection of 
