ZOOPHYTA HELIANTHOIDA. 197 



The body of the Helianthokla may be compared to a trun- 

 cated cone or short cyHnder, seated on a flat plain base, while 

 the opposite end is dimpled in the centre with the oral aperture, 

 and garnished with variously figured tentacula which originate 

 from a space between the proper lip and the free somewhat 

 thickened border of the disk. In a state of contraction the 

 mouth is closed, the tentacula are shortened, and the whole 

 concealed by this border, being drawn like a curtain over them, 

 leaving a mere depression on the top. The mouth leads by a 

 very short and wide passage into a large stomach, which is a 

 membranous bag puckered internally with numerous plaits, and 

 divided in a perpendicular direction into two equal halves, by a 

 deep smooth furrow with cartilaginous sides, as was first remark- 

 ed by Reaumur.* There is no intestine, nor any other visible 

 exit from the stomach than the mouth, bv which the undigested 

 remains of the food are ejected, always enveloped in a large 

 quantity of a clear glairy fluid. But in a state of expansion and 

 of hunger, many kinds of Helianthoida can protrude the stomach 

 beyond the lip in the form of large bladder-like lobes, which 

 often hang over the sides and almost conceal the rest of the 

 body ; and amidst them there are very frequently extruded at 

 the same time some white filaments, like bundles of ravelled 

 thread, which have escaped either through a rupture, or a cir- 

 cular opening in the bottom of the stomachal membrane. The 

 space between the walls of this organ and the outer envelope is 

 divided into numerous narrow compartments by perpendicular 

 and parallel lamellae of a musculo-tendinous texture, which ex- 

 tend from the oral disk to the base, and radiate to the centre 

 like the gills of a mushroom to its stalk, — a comparison the more 

 exact as some only of the lamellae reach and touch the stomach, 

 the rest coming more or less short, and forming consequently 

 imperfect interseptal spaces. " The breadth of the leaflets va- 



* " They (the furrows) are produced on each side by the firm adherence of 

 the gastric membrane to a i)air of very dense, fleshy, but narrow leaflets, through- 

 out their whole extent, or, in other words, from the top to the bottom of their 

 internal border. These depressions divide the animal into two lateral halves, 

 constituting a bilateral symmetry in Actinia, as has been observed by M. Agassiz 



in other supposed radiated animals." Teale in loc. cit. 102 But in Actinia 



Dianthus the channel or furrow exists on one side only. 



