Ser. CHLOROSPERMES. Fam. Dasycladec. 
Puate CCXLIX. 
ACETABULARIA CALYCULUS, Quoy et Gaim. 
Gen. Cuar. oot scutate. Frond stipitate, umbrella-shaped, thinly in- 
crusted with carbonate of lime. Sfzyes tubular, unicellular, cylin- 
drical, crowned with a peltate disc formed of numerous radiating 
cuneiform cells. Ced¢s of the disc at first containing granular green 
matter, which is afterwards changed into spherical spores.—Acerra- 
BULARIA (Lamea.), from acetabulum, a saucer. 
Radix scutata. Frons stipitata, umbraculiformis, tenuiter calcareo-incrustata. 
Stipes tubulosa, monosiphonia, cylindracea, disco peltato e cellulis pluribus 
cuneiformibus formato coronata. Disci cellule primo materie yranulart viride 
replete, demum sporis sphericis farcte. 
ACETABULARIA Calyculus ; peltate disc cup-shaped ; its radii incurved. 
A. Calyculus ; disco peltato calyciformi, radiis incurvis. 
ACETABULARIA Calyculus, Quoy e¢ Gaimard, in Freycinet, Voy. Zool. t. 90. 
f. 6,7. Kitz. Sp. Alg. p. 510. 
CLIFTONELLA Calyculus, J. H. Gray, in Ann. Nat. Hist. ser. 3. v. 8. p. 408. 
Has. West coast of New Holland, Quoy and Gaimard. Dredged in 
Owen’s Anchorage, Fremantle, Western Australia, G. Clifton. 
Groar. Distr. West coast of New Holland. 
Descr. Root a minute disc. Fronds tufted, 1-3 inches high. Sécpes setaceous, 
thinly incrusted with carbonate of lime, whitish, opaque, distantly nodulose, 
pierced at the nodes by a circle of small holes or scars (being the points of 
attachment of whorls of byssoid fibres, which accompany the early stages 
of growth). Disc campanulate or cup-shaped, very concave, formed of 
numerous, strongly-incurved or arched, lineari-cuneate, blunt-topped cells, 
which are at first filled with yellowish-green grumous matter, and at matu- 
rity with innumerable spherical spores. The spores are perfectly globose, 
bright green, and have a toughly-membranous hyaline coat. The substance 
is rigid, and in drying the frond does not adhere to paper. 
The genus Acetabularia at present includes three species: 
one of them a native of the Mediterranean Sea; another, of the 
West Indies and the tropical ocean generally; the third, the 
subject of our figure. ‘This Australian species is at once known 
