80 ZOOLOGY. 
dently, is called the columella, while the small separate pillars 
between the columella and the septa are termed paluli. In 
the compound or tree-like corals, each young coral polyp 
forms a calicle, theca, or limestone support of its own, which 
unites with the other by calcification of the connecting sub- 
stance of the common body. This intermediate layer is 
termed cenenchyma (Huxley). 
The simpler corals consist of but a single calicle contain- 
ing one polyp, as in Flabellum, Deltocyathus, and Caryo- 
phyllia. They live free, fixed in the mud in deep water, 
and occur in water with a temperature of about 32° Fahr. 
Flabellum angulare Moseley has been dredged off Nova 
Scotia in 1250 fathoms. 
Deltocyathus Agassizii, which is not uncommon in the 
Florida channel, at depths varying from sixty to three hun- 
dred and twenty-seven fathoms, has been dredged by us at the 
mouth of Massachusetts Bay, in one hundred and forty fath- 
oms (temperature 39° to 42° Fahr.). An allied form is 
Ulocyathus arcticus Sars, said by Duncan to be the same as 
Flabellum laciniatum Edwards and Haime, a fossil of the 
late tertiary, dredged by us in one hundred and fifty fath- 
oms, near St. George’s Banks, Gulf of Maine. 
In the family of which Oculina, the eye-coral, is a type, 
the polyp stock is compound, branched, increasing by lat- 
eral buds. Lophohelia prolifera Pallas (Fig. 53) occurs 
in the seas of Norway, and has likewise been found to occur 
on the banke off Nova Scotia and Newfoundland, while it 
lives in the Florida Straits, in from 195 to 315 fathoms. 
In Meandrina, or the brain-coral, Pavia, Astreaand As- 
trangia, we have representatives of the important group 
Astr@acea, in which the corallum is massive, more or less 
nemispherical, and the polyp-cells or calicles are distinctly 
lamello-radiate within, and generally so without. Budding 
is usually carried on by division of the disks, or by spon- 
taneous fission. In Mussa the polyps are sometimes two 
inches in breadth, as large as ordinary Actinie. Diploria 
cerebriformis Edwards and Haime is a brain-coral which is 
eommon in the West Indies and at the Bermudas, some. 
