48 ZOOPHYTES. 
commencing immediately at the mouth, and others rising to fill up 
the spaces between them as these diverge. Although so unlike the 
type in external shape, yet the actual structure is closely similar, for 
the Fungia is nothing but an Actinia spread out laterally into a broad 
flat disk. The inequality in the lamelle is much greater, though of 
the same character, and the tentacles are more widely scattered, so as 
to lose all appearance of being in series. ‘The connexion between the 
formation of a tentacle and a new lamella within the animal, is finely 
exemplified in the Fungia; for each tentacle rises where a new ridge 
reaches the surface, and their formation is constantly going on as 
the animal enlarges and new ridges rise. This may be seen by 
reference to the figures of Fungiw on plates 18 and 19, where 
the small prominent tubercles scattered over the surface are the 
tentacles.* 
The close relation of the Fungia to the common Actinia is thus 
evident; yet in the actual form of the visceral cavity they are quite 
unlike. Instead of a cylindrical space, divided into shallow compart- 
ments by erect fleshy lamelle, we have here long horizontal compart- 
ments, commencing at the mouth, and as they enlarge outward, con- 
stantly subdividing by the growth of new lamelle: these lamelle, for 
a while before rising to the disk, range along the bottom of the cavity. 
Unlike the Astras, the Fungi never cover the contracted tentacles 
by the involution over them of the margin or surface from which they 
rise; there is actually no margin to the disk in these animals: more- 
over, in compound species, the visceral lamelle of adjoining polyps 
are continuous from one to the other, and it is probable that the sub- 
divisions of the visceral cavity are also directly continuous, so that in 
these compound Fungi we appear to have a community of visceral 
cavities, as in the Hydroidea, differing from the latter, however, in 
having the communications by lateral or interseptal spaces, instead 
of by the lower extremity of the cavity. In the Astras, the same 
communication in effect takes place, though less perfect, through the 
open pores or lacunes, which pass laterally from one polyp to another. 
The Fungi afford the nearest approach, among zoophytes, to the 
Acalephe. 
There is often in a Fungia, a line running from one or more sides 
of the oblong mouth to the circumference, along which some of the 
* On account of the small size of these organs, at has been denied that they are tenta- 
cles. Yet, whether so called or not, they correspond to the tentacles of the Actiniz ; and 
in some species of Actinia they are as short and scattered (see plate 4, figure 32). 
