CELL, VEGETABLE. [CELIA; IllaTOLOOT; Tissrra, VDIETADLY.) CEL LARI A. [CELL& L.EA.] CELLAItIiEA, or CELLA RIAD.rE, the twain(' family, according to Do Blainvillo's arrangement, of the sub-class i'otyphria ifonbranacre.
Animals hydrifonn, provided with very delicate ciliated tentaculn, separated, distinct, contained in oval flattened membranous collides, with a bilateral subtormined crescentic) opening ; usually provided with a moveable cartilaginous lip, forming by their lateral junction, in one or two tiers or stages, a cretaceous or membranous, limited, diversiform, and fixed polyzoarium. Ovicells external, globose, above the aperture of the cell.
This group corresponds pretty nearly with the Escharader, Flustradm, and Cellariack of Fleming, and the I.:scharina and Cdleporina of Ehrenberg; it also includes part of the sub-order Cheilo stomata, of the Polyzoainfundibulata of 31r. liusk's 'Catalogue of Marine Polyzoa.' For further particulars respecting the structure of the animals and their habitations, reference must be made to PlATZOA, few only of the principal forms being here noticed.
We shall notice here the principal generic forms of this group.
1. Lunelites. The number of species of this generic group, of which until lately only a few fossil forms were known, has been much augmented by the addition, not only of other fossil species, but also of several recent ones. The latter have also afforded n much more precise insight into the structure of the peculiar polyzo arium than it was possible to obtain from the inspection merely of fossil specimens. The division of the genus suggested by LainourOux seems to be sufficiently founded in nature to justify its definitive adoption so far as it goes ; and, in addition, a recent form described and figured in the Voyage of 11. AI. S. Rattlesnake' would seem to indicate the propriety of instituting a third generic or sub-generic type.
In all these forms the polyzoary, which is more or leas regularly circular, convex above, and concave or flattened below, presents cells of two kinds—one set of which may be termed secondary or accessory ; and it is according to the relative position of these cells as regards the others that the division of the genus is founded.
In one case the secondary cell, which is then considerably smaller than the other, is situated at the apex of the primary cell, immediately above the aperture (Cupularia). In a second form any distinction of size between the two sorts of cells is lessor not at all obvious. The two seta of cells however are very differently arranged from those in the former case ; the secondary being disposed more or less regularly in longer or shorter rows, alternate with the others, and like them radiating from the centre (Lunalites). Of the former of these forms the Lunulite en Parasol of Defrance maybe taken to afford a tpe, and of the latter, L. radiata. In the third form the secondary cells are scattered more irregularly over the surface of the polyzoary. In this case the secondary cell is also superior to one of the other kind.
From the examination of recent forms it has been ascertained that the secondary cell probably contains nothing more than a MAC of muscular substance for the movement of a vibratile spine or seta, of various forms and structure, and which corresponds with the vibra culum, or moveable setose organ, which is found on several of the Polyzoa, and particularly in the genus Scrupoccllaria.
The arrangement of the group therefore into three genera would appear to be justifiable and convenient, namely, Lunitliles, Cupularia, and Sdsnaria; which may be thus defined :— Lunulites, Lamouroux. Polyzoarium circular or irregular, con vex above, concave or flattened beneath ; cells arranged in series radiating from the centre, and separated by alternate rows of cella supporting vibracular spines; under surface usually with radiating stile, and the surface with minute perforations. Recent species : L. capulus, Busk; Voyage of Rattlesnake.' L. gibbosa, Busk ; 'Cat. Brit. Alus.' pL 112.