ANTHOZOA HELIANTHOIDA. 183 



phere of a fleshy consistence, or elongating themselves into a 

 sort of flabby cylinder that indicates a state of relaxation and 

 indolent repose. 



The Actinia coriacea is the principal species which the 

 anatomist has examined with care,* and it may safely be 

 chosen as the representative of its order, the ^probability being 

 that the deviations from its structure in the other species and 

 genera are only of secondary consequence. Of the species 

 mentioned Mr. Teale has given a very elaborate anatomy,f 

 more correct and minute than any hitherto published, but the 

 sketch to suit our design, must be of a more general character. 



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

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

 the ojjposite end is dimpled in the centre with the oral aper- 

 ture, and garnished with variously figured tentacula which 

 originate from a space ('peristome) 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 remai-ked by Reaumur, j There is no intes- 

 tine, nor any other visible exit from the stomach than the 

 mouth, by 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 



* M. Delle Chiaje has, it seems, anatomized several other species, but I cannot 

 read his work, which is written in the Italian language. For a similar reason I have 

 not been able fully to avail myself of the writings of German naturalists. 



t " On the Anatomy of Actinia Coriacea, by Thomas Pridgin Teale," in Transac- 

 tions of the Leeds Philosophical and Literary Society, vol. i. 



J " They (the fiurows) are produced on each side by the firm adherence of the 

 gastric membrane to a pair of very dense, fleshy, but narrow leaflets, throughout 

 their whole extent, or, in other words, from the top to the bottom of theii- 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 plumosa the channel or 

 furrow exists on one side onl}'. 



