250 ALGH ANTARCTICA. 
ginea compressa lineari bi-tripinnata cireumscriptione an- 
guste lanceolata, pinnis pinnulisque omnibus oppositis 
_ basi apiceque attenuatis acutis erectis v. ultimis appressis 
margine integerrimis. 
Has. Falkland Islands, abundantly, and Hermite Island, 
Cape Horn. 
Fronds many feet in length, of a singularly narrow-lanceo- 
late outline, bipinnate in the lower and upper part, triply pin- 
nate inthe middle. Stems 2-3 lines in diameter, branches 
1 line, all remarkably tapering to the base and apex, and all 
inserted at a very acute angle, so as to be nearly erect. It 
most resembles a very narrow form of D. ligulata, but is of a 
much coarser and thicker texture. Besides these new spe- 
cies, D. ligulata, media and viridis, were found abundantly in 
the Antarctic Seas. 
4. Dictyosiphon fasciculatus, nob. in Flor. Antarct, v. l, 
p- 178, t. 69, f. 1. 
Has. Lord Auckland’s Group. 
STEREOCLADON, Nov. Gen. 
Frons solida, olivacea, filiformis, ramosissima, e cellulis endo- 
chromate repletis longitudinaliter seriatis formata.  Spori- 
dia solitaria, sparsa, in frondis peripheria immersa, nigro- 
olivacea, elliptica.— Genus dubiæ affinitatis, vix in tribu 
Dictyotearum includendum. 
5. Stereocladon Lyallii, nobis. 
Has. Cape Horn and the Falkland Islands. 
Frons 5-6 uncias longa, setacea, decomposito-ramosissima, 
ramificatione valde irregulari. Caulis percurrens v. parce 
divisus, vix dichotome ramosus. Rami alterni, patentes, 
flexuosi, decompositi; ramuli omnes patentes, flexuosi V- 
squarrosi, multifidi ; sapices acuti. Substantia rigidula, 
charte laxe adherens. Color olivaceus. Sporidia nu- 
merosissima, per frondis partem. ipea dense sparsa; 
immersa. 
. This remarkable plant resembles to the pow eye : Dictyo- 
