1816.) - Royal Institute of France. 465 
in stars round a common centre; and these naturalists, considering 
each star as a simple animal, have called botrylle; others in fine 
are combined in innumerable quantities, to form by their assem- 
blage a long hollow cylinder, open at one end, which moves like 
the sea pens, and which Peron, the first person who perceived it, 
considering as a simple being, called pyrosoma. 
MM. Desmarets and Lesueur had made on these last two genera 
observations quite analogous to those of M. Savigny, and which 
have fully confirmed them. 
There exists among those great zoophites to which the ancients 
gave the name of free nettles of the sea, a genus which the Danish 
naturalist, Otho Frederick Muller, has made known, and called 
lucernaria, because he found in it 1 know not what resemblance to 
a lantern. Its general form is a hollow cone; at the centre of the 
base is the mouth; and from the edges of that base proceed arms 
usually eight in number, charged with small tentacula, sometimes 
at equal distances, sometimes connected in pairs. 
M. Lamouroux, Professor of Natural History at Caen, has care- 
fully watched an animal of this nature with eight equally distant 
arms, of a pale rose colour, dotted with red, and having eight red 
bands penetrating into the base of the arms, and which are the 
ccecums or intestines. These eight organs communicate with a 
central stomach. Each of them is lodged in a particular cavity, in 
which a kind of mesentery retains it. ‘The kind of life, of the 
jucernarie seems to resemble that of the actiniz, or sea anemonies. 
The same naturalist has presented to the Class a new compendium 
of his general work (of which we have before spoken) of these kinds 
of compound zoophites, whose trunks are not stony, or, as he calls 
them, flexible coralligenous polypi, such as the sertulariz and the 
flustre. The profound attention which he has paid to these animals 
in general has enabled bim to remark distinct characters sufficiently 
remarkable to form nearly 50 genera, which he has divided into 10 
families, and under which he has arranged 560 species, almost the 
half of which are new. 
We can only repeat the wish that this great work may be speedily 
published. 
M. Leclere de Laval, the same person who examined the con- 
fervee, has presented to the Class some interesting observations on 
some microscopic animals. One of them, which M. Leclere has 
discovered, and called diflugia, is scarcely the tenth of a line in 
diameter, is enveloped in a membranous case formed of very fine 
sand, and from which a kind of arms issue, which are merely an 
extension of its substance, and of which the number, the form, and 
the proportions, vary almost at pleasure. ‘This animal ought to 
have an analogy with that which Reesel called proteus, and which 
likewise assumes in a few minutes a thousand different forms. 
The other animal observed by M. Leclerc is a hymenopterous 
insect, discovered by M. Jurine, Correspondent of the Class, and 
called by him psile debosc, but which belongs to the genus diupria 
