284 
Acecrant qf^l, Lyngbye’s 
server, we cannot help feeling, that his system wants that cer» 
tainty and distinctness which is required in all works of this de- 
scription. 
But the most scientific and satisfactory arrangement of the 
Algse hitherto proposed, is that of H. Christian Lyngbye, author 
of a most valuable work, in 4to, printed at Copenhagen in 
1819, at the expence of the King of Denmark, under the title of 
“ Tentamen Hydrophytologise Danicas ; cum Tab. sen. 70.” It 
contains the results of numerous journeys, and of long, patient, 
and careful investigation. The arrangement, which is all that 
interests us at present, is founded on the seeds, and on differen- 
ces in the form and structure of the plants. The following view 
of the arrangement, with the character of the Orders ( Sectiones) 
and Genera, we have no doubt will prove very acceptable to 
our botanical readers. 
HYDROPHYTA. 
A. Frondosa. 
a. Continua. 
a. Solida. — Sect. I. Phycoidata. 
a. a. Fronde plana. 
1. Fncus. Frons plana dichotoma olivacea. Receptacula termi- 
nalia, turgida intus mucosa, tuberculis numerosis sphagricis fibrisque 
intertextis repleta. 
2. Delesseria, Lam. Frons plana membranacea costata rosea, 
Semina nuda frondi immersa, vel tuberculosa globosa innata. (F. 
sanguineus, sinuosus, et alatus.) 
3. Odonthalia, Lyngb. Frons plana membranacea subecostata 
dentata rubra. Siliquse axillares lanceolatae. (F. dentatus.) 
4 Spceivcocciis, Stackh. Frons plana membranacea ecostata ru- 
bra. Tubercula globosa ad marginem sessilia. (F. membranifolius> 
Brodiaei, palmetta, laciniatus, ciliatus. Turn.; cristatus, L. ; mam- 
millosus.) 
5. Chondrus, Stack. Frons plana dichotoma vel ramosa rubra. 
Tubercula hemisphaerica, apicibus frondis innata. (F. crispus, Nor- 
Vegicus, rubens, L. ; laceratus, Gmel. ; Bangii, FI. Dan.) 
d. Zonaria, Draparn. Frons plana orbiculai‘is oppressa. Se- 
mina nuda, in lineas transversales concentricas. disposita. (F. fun- 
gularis, FI. Dan. 420.) 
7. Laminaria, Lam. Frons plana stipitata olivacea, radice fibrosa. 
Semina nuda frondi immersa. (F. digitatus, bulbosus, saccharinus, 
esculentus, phyllitis, agarum. Turn.) 
8. Ulva. Frons plana expansa. Semina nuda, substantive frondis 
immersa. (F, palinatus, L.; edulis> soboliferus, fascia. Turn.; 
