60 . CORALS AND CORAL ISLANDS. 
Zovthome. — The compound animal mass produced by budding. 
Corallum. — The coral either of the compound mass, or of the solitary 
polyp. 
Corallet (In Latin, corallulum). — The coral of a single polyp in a com- 
pound corallum. 
Calicle. —The polyp cell in the top of a corallet, or of a solitary 
corallum, within the walls of the cells; it is sometimes flat at top, that is, 
without the usual depression. 
Septa. — The radiated plates of the cell or calicle. 
Dissepiments. — Small cross plates between adjoining septa, approxi- 
mately horizontal; sometimes wanting. 
Synapticule.— Calcareous bars extending across the interseptal spaces, 
or loculi, and so uniting the surfaces of adjoining septa. 
Tabule. — Horizontal plates dividing the interior of a cell into a 
series of chambers, as in the ancient Favosites, and in the Pocilliporee. 
Tabulate. — Waving tabule. The Tabulate include the Favosites and 
some other ancient corals. 
Columella. — The prominent axis of a corallet projecting at the centre 
of @ calicle. It is generally absent. 
Coste. — The vertical ridges over the exterior of some corals; they 
usually correspond to the sept, and are an external extension of them; 
but in other cases they are opposite the intermediate chambers, or are 
interseptal Joculi, as they are often called. 
Ceenenchyma.—'The common mass of the corallutm between its dif- 
ferent polyp cells or corallets, as in the Madrepore, Gemmipore, and 
Dendrophylliz. 
Epitheca.— The coral layer sometimes deposited over the exterior of 
the corallum during the life of the polyp by the outer skin before it dries, 
away, as explained on page 44. 
Peritheca. — The epitheca of a compound group or zoothome (fig. p. 71). 
Exotheca.— The portion of the corallum outside of the walls of cells 
in many coralla of the Astreea family, and some others, in which the polyps 
of the mass are properly in contact, and there is consequently no true 
coenenchyma. 
Endotheca. —'The portion of the corallum inside of the walls of the 
cell. 
We may now state briefly the characteristics of the 
grander divisions of the Actinoid polyps, several of which 
have been illustrated in the preceding figures. 
