540 ALGÆ NOVÆ ZELANDIA. 
— Algæ Australasicæ substantia habituque ad Halymeniam, — 
structura tamen ad Laurenciam affines. Apices ramulorum. 
obtusissime. 
In this group we propose to include, beside the two . 
following species, the Laurencia ? membranacea of Harv. in ; 
Hook. Journ. (Cladhymenia Gunnii, Harv. MS.), although | 
as yet we are only acquainted with the tetraspores of that - 
plant; and although there is a slight discrepancy in the 
structure of its frond, the stratum of minute surface cel- 
lules being nearly obsolete. Still, the habit is so completely - 
similar to that of the following species that we think it may 
with safety be referred to our new genus. The ceramidia, — 
if such they may be called, are certainly the lowest deve- - 
lopment of that organ with which we are acquainted, being - 
no more than slightly inflated ramuli, scarcely shorter than | 
the unmetamorphosed ones, containing at the bottom of the - 
inflated portion a tuft of unequal angular seeds. 
69. Cladhymenia Lyallii, nobis ; radice fibrosa ramosa, fronde - 
angusta nervo obsoletissimo percursa gelatinoso-membra- 
nacea bi-tripinnatifida, laciniis lineari-lanceolatis basi an- 
. gustatis patentibus apicem versus brevioribus, supremis — 
simplicibus, inferioribus elongatis pinnatifidis bipinnatifi- 
disque, ramulis filiformibus obtusis, ceramidiis elliptico- - 
oblongis pedicellatis. : 
Has. Bay of Islands, Lyall. 
Fronds 4-5 inches high, in circumscription broadly del- 
toid, filiform at base, quickly becoming flat, and gradually ; 
acquiring the breadth of one, and in the middle of 2-3 iines, 
and thence tapering to the apex, traversed by an obsolete in- 
ternal nerve like that of certain Plocamia, repeatedly pin- 
 matifid. Pinne tapering at both extremities like the main - 
stem, the lowest bipinnatifid, the middle pinnatifid, the. up- 
permost simple or merely toothed; ultimate ramuli Hine : 
filiform, obtuse. Colour a fine rosy red. 
70. Cladhymenia oblongifolia, nobis; radice bros ramosa, 
fronde latiuscula enervi gelatinoso-membranacea pinna- 
tifida et € laciniis ho m dE Meme 
