Madreporarian Genus Astreopora. 281 
Heliopora cerulea*, in which the tubes of the Annelids 
are more numerous than the polyp-cavities, and must exercise 
a powerful influence on the’ growth of the corallum. 
Among the Astreoporans I have found two cases. One isa 
single specimen (A. Kent?, sp. n.) discovered by Mr. Saville 
Kent on the west coast of Australia, in which only a few 
tubes were present, and appeared somewhat to disturb the 
coral, The other (A. gracilis, sp. n.) is from the Solomon 
Islands, and was discovered by Dr. Guppy. In this case the 
worm-tubes interlace with the long polyp-cavities, and open 
on the surface in great numbers, both coral and worm being 
apparently adapted to one another. The tubes are often pink, 
and even red, in colour, and much larger than those found 
in Heliopora, ca. ? millim. in diameter, as compared with 
ca. + millim. 
EXPLANATION OF PLATE XIV. 
Fig. 1. The youngest specimen found, consisting of a parent-polyp (pe), 
with a group of daughter-polyps developed chiefly.on one side, 
the whole corallum contained in a saucer-like epitheca(e). The 
daughter-polyp (a) is developing in contact with the epitheca, 
which forms part of its wall. 
Fig. 2. Diagram to explain the pulvinate method of growth. The 
corallum rises from the original epitheca e’, the corallites 
lengthening greatly in the middle. As the lower parts die, the 
top expands as shown ; under the edge of the overhanging top 
a secondary epitheca, e’’, develops, and appears to restrain the 
downward flow. 
Fig. 3. Largest specimen, showing the pulvinate type of growth, deve- 
loped on the edge of a dead overturned previous growth. a, 
the former top of the dead growth. 
Fig. 4. Diagram illustrating the globular method of growth. The original 
youngest growth is hollowed out by boring mollusks. e’, the 
edges of the original epitheca; e”, e'’, ey, folds of secondary 
epitheca which have restrained the downward flow of the living 
layers. At a the living layer is beginning to roll over the 
epithecal fold. 
Fig. 5, Specimen of Astreopora punctifera, Lamarck, showing four 
layers. The first (1) has been overturned; its corroded upper 
face is seen in the plane of the paper; at a the coenenchyma is 
rolling over the epitheca. 
Fig. 6. Typical structure of the ccenenchyma (from A. Ehrenbergii,= 
A. myriophthalma, Klunzinger, non Lamarck). The synap- 
ticular floors form nearly regular tiers, supported by tapering 
costal echinule. 
* Cf. Moseley, Phil. Trans. vol. clxvi. pt. 1, 1876, p. 96, and Saville 
Kent's ‘ Great Barrier Reef, pp. 192-194; also, for the case of Mycedium 
Fragile, cf. Fewkes, ‘ American Naturalist,’ vol. xvii. p. 595 (1883). 
