L. cancellata, Busk ; pl. 113.
Cupularia, Lamoureux. Polyzoarium circular, regular, convex on the upper aide and concave below; cella disposed quincun cially, each with a smaller vibracular cell at its summit ; under surface with radiating lines, grooves, or ridges, or divided into sub-hexagonal areas; surface perforate or imperforate, smooth, or granular.
Recent species : C. Guineensis Busk; 'Cat. Brit. lrus.,' pl. 114.
C. th ' eenii Gray ,t ph C. Loicei,Gray ; 11 11 pL 116.
C. stellata, Busk ; ,,pl. 118.
Busk; 'Cat. Brit. Daus.' Polyzoarium circular, regular, convex above, concave below ; cells disposed quincuncially, some (closed in front by a cribriform calcareous plate) furnished with a superior vibraculum.
Recent species : AS niaculata, Busk; Voy. of Rattles. ' Cat. Brit. Mus.,' pl. 117. Example, Lunulites red let a. Locality, Grignon, &e.
2. Electra. ' Animals unknown, contained in membranous vertical bell-shaped cellules, ciliated en the edges, and shut by a diaphragmatic membrane, with a very small and semilunar opening, and disposed in a verticillate form around an ideal axis.
Example, Electra rerticillata.
with innumerable cells sunk in its substance, which are inhabited by vivacious hydra. Different species or varieties occur in the Scottish seas, especially the gelatinosum, and a thin green flattened palmate kind, which has perhaps escaped the notice of naturalists hitherto. A white, opaque, ovoidal or nearly circular flattened corpusculum, previously invisible, issues from the fleshy part of these products whence it seems to be elicited, particularly by the influence of light. On removal of a small specimen that had already afforded many from a dark situation to a moderate degree of light, at least 150 quitted their recesses within an hour. These beings are endowed with much greater activity than the corpuscula of the Actinia; their courses are alike diversified ; they swim through the water in all directions, regu larly and irregularly, ascending to the surface or descending to the bottom, pursuing a straight line, describing an orbit, or tumbling about among the neighbouring substances. Meanwhile, as if of soft
consistence, their form alters, and the action of the cilia environing the body is alternately depressed and relaxed. At length, having become stationary, a margin diffuses around the body, and supervening trans parence of the centre soon exposes an inanimate hydra within, which in nine or eleven days is displayed perfect from its cell. The inner surface of each tentaculnm is now clothed by a double row of stout dark cilia in rapid motion, but in opposite directions ; for as those of one side strike upwards those of the other strike downwards. Further diffusion of the basis adhering below forms additional compartments for other hydrae. The propagation of the Flustrce carbasea, foliacea, and truncata ensues after a similar fashion. A ciliated corpusculum, spherical, ovoidal, or irregular, quits the leaf, pursues its course in the water, becomes stationary, adheres, and a nascent Flustra arises from the spot. Above ten thousand such corpuscula have been produced by a moderate-sized specimen of the Flustra foliacea, tinging the bottom of a vessel yellow from their multitude, and vitiating the water by their decay. The same author, in the Proceedings of the British Association' (Edinburgh, September, 1834), thus clearly and elaborately describes the organisation of Flustra carbasea :" The Flustra carbasea re This is the Flustra verticillata of Gmelin (Sertularia rerticiltata of Esper) ; and this genus, which was separated by Lamoureux, scarcely deserves, as De Blainville remarks, to be distinguished from Flustra pilosa, whose cellules are occasionally somewhat verticillated ; but in this he confounds two things perfectly distinct, though often misconceived.
3. Flustra. Cells contiguous ; on both sides of the frond.
4. Carbasea. Cells contiguous ; on one side only of the frond. Example, Flustra carbasea. Locality, seas of Scotland, &e.