518 
ZOOPHYTA. CORALLINAD . Alcyonium. 
aggregate fleshy tubular cells of polypi, having about 12 radiating short ten- 
tacula. It is the drying of the tubes that forms the rigid spinulie.” 
89. A. parasiticum.- — I place here provisionally a parasitical 
species, which invests the old stalks of several of the Sertula- 
riadce. It is destitute of fibres, but strengthened by denser 
bands, which, by anastomosing irregularly, enclose the spaces 
of the cells ; these seem to have rounded orifices, and to be dis- 
tant from each other ; the surface is rugose when old, the ori- 
fices of the cells become more apparent, and the whole much 
mixed with mud. I have not had an opportunity of observing 
it in a recent state. ^ 
Gen. XLI. CRISTATELLA. — Body gelatinous, brandi- 
ed, with terminal polypiferous papillae ; the cirde of tenta- 
cula disposed in the form of a crescent. 
90. C. campanulata.—Bodiy divided, palmate. 
Polype a panache d’eau douce, Trembly^ Pol. p. 227* t . x f: d, 9, — Tubu 
laria camp. Linn. Syst. 1303. Berk. Syri. i. 215. Brit. Fauna, 
211 — Adheres to liemn^. 
The body is translucent and palmately branched, the end: the brandies 
forming cells ; the body of the polypi is cylindrical, where e;>:ser narrow at 
the summit, with numerous tentatacula ; an esophagus, stem. • \ and intestine, 
together with two threads, descending into the fleshy base, ; fe observable. 
It may admit of doubt whether the animal described b v il f esel (hi. 551>, 
t. xci.) constituting the Cristatella mucedo of Cuvier, and tvt.n ..-dla vagam of 
Lamarck, and which is/rec, belongs to the same genus ti j, Pohiije a pa- 
ncLclie of Trembly, above referred to, -which seem to he fixed., fiyid to be near- 
ly related to the genus Plumatella. 
SPONGIAD^. 
The sponges, which have long occupied the attention of naturalists, 
and given rise to considerable difference of opinion regarding their 
true place in the System of Nature, have at length been examined 
by an observer possessing the requisite leisure, opportunity, industry, 
and talent for conducting such intricate researches. I here refer to 
the papers which have appeared in the Edinburgh Philosophical Jour- 
nal by Dr R. E. Grant, now Professor of Zoology in the University of 
London. He has succeeded in determining the functions of the pores, 
and the origin and mode of development of the ova. 
Sponges consist of an albuminous skeleton and gelatinous matter, 
forming a mass not irritable, with numerous holes, connected internal- 
ly with anastomosing canals. The skeleton is either simple, consisting 
