10. Ceeent.
Body gelatinous, free, regular, very short, but extended or prolonged on each aide into a long riband-like appendage, bordered on each angle with a series of vibratory cilia, thus forming four ambulacra, two on each side. Mouth inferior and menial, accompanied by a pair of long, ciliferous, retractile and simple appendages.
Example, Cesium reneris, Lesuenr.
Although there is not much resemblance bet %Ten this singular genus and the typical forms of Ciliograda, yet they are connected by a succession of intermediate links. If we refer to the genus Call Ian ire, we shall find that its globular body is so extended laterally as to have a wing-like appendage on either side. In other genera these lateral ap pendages are still more extended, until the globular body in the centre is entirely lost. The ali mentary canal of astern runs across the middle of its length, and from it extends, as from the stomach of the Medusa., a series of gastric canals which carry the nutriment to all parts of the body.
The third order is the Claim GRADS. They are thus called from the cirrhi winch arc attached to the disk upon which their organs are disposed. These cirrhi are, some of them, tubular, and are furnished with suckers. The cwcal appendages are attached to their base, in which are pro duced the ova, which pass out at the mouth of the cirrhi. The following is Do Blainville's defi nition of the order :— Body, oval or circular, gela tinous, sustained in the interior of the dorsal disk by a solid sub cartilaginous part, and provided on the lower surface of the disk with tentaculiform cirrhi, which are very extensible.
Genera. 1. re/ella.
Body membranous, oval, very much depressed, convex, swollen, sustained above by a transparent oval subcgrtilaginous piece, marked with concentric Arias and surmounted by a vertical and oblique crest, concave below, with a sort of menial nucleus, offering a central mouth at the extremity of a proboscidiform prolongation, surrounded by tentacular cirrhi of two kinds, the external being much longer than the internal ones.
Do Blainville obeervon that Imierato and Columua would appear to be the authors who first noticed the animals which constitute this Benue, established, at first, under the name of Phyllidoee, by Patrick Browne, and figured by him in his 'History of Jamaica,' tab. 48, jig. 1.
Forskahl, who gave a very good description of it, arranged it under his genus Hololh aria. LectlinF made it Medusa, denominating the species known to him Medusa reklla, a name adopted by Linniens in the • Systema Naturre: Dana (' Soc. boy. de Turin,' 1766) proposed the name of A rmenistares for it; and Lamarck published it under thogenerio appellation of Facile, by which it is now generally known to naturalists.
This form is widely diffused, and has been found in the seas of Europe, America, Aain, and Australasia. One of the species, hotbox!, is often taken on the southern coasts of England. The animals are met with far at sea, and often huddled together, young and old, in con siderable masses. :Wien; are said to fry and eat them.
The Phyllidoce labris arruleis, the Sally-Man of Browne, appears to be the relella cyanea, of Lesson and Garnot, and one at least of the species which gave rise to the Medusa relella of Linea us and Cumin' (Lamarck quotes the last name as well as Browne's Ph yllidoce, as synonyms of his rdella mutica).
2. Pataria.
Body oval or circular, sustained by a subcartilaginons, compressed, elevated piece, with a muscular, moveable, longitudimd crest above, concave below, and provided in the middle with a free prolsoseidiform stomach, and with a single row of marginal tentaculiform suckers.
Eschscholtz established this genus for some very small eirrhigrade animals, whose back is sustained by a kulear tilaginous piece, not elevating itself in the dorsal cavity, and which only offer marginal cirrhi on the central surface. Do Blainville, after observing that Forskahl has figured with his 'kilobit uria spirans (Melia limbosa of Lamarck) some very small animals, which 3L Eschscholtz himself regards as closely approximating to his Rataria cordate, says that it seems possible that the Pataria. may be only degrees of development of l's/s//a. Example, Ralaria milrata.