68 
THE SEAWEEDS 
Sargassum Merrifieldii J. Agardh. 
Stems of the fronds angular, rounded rough. Leaves narrowly linear, 
almost entire, with a single row of cryptostomata on each side of the midrib, 
to 5 cm. long and about 2 mm', wide. Vesicles rather few, larger than in 
preceding, mutic, on a petiole about as long as the diameter. Receptacles, 
compound when mature, then subracemose on a very short ram ulus, singly 
ovate-lancoid, smooth, warted. 
Only known from South Australia. 
Sargassum spinuligerum Sonder. 
Stems of the fronds compressed, above subangulate, firm, of the thickness 
of a pigeon s quill, often nyuriculate with minute spines. Lower leaves less 
toothed, to 5 cm. long and 8 mm. wide, with scattered cryptostomata. 
upper lanceolate, serrate-dentate, with a single row of cryptostomata on 
each side of the midrib. Vesicles spherical, mutic, of moderate size, on a 
petiole as long as the diameter. Receptacles lancoid, smooth, 4 to 7 mm. 
long, at length racemose on a rather elongated ramulus. 
On all the coasts of Australia except the north, and extending to New 
Zealand. 
SEIROCOCCUS Greville. 
llieie being but one species, genus and species have the same characters. 
Seirococeus axillaris Greville. 
. Attachment a disc, throwing out numerous branching and clasping 
fibres. Frond 90 to 180 cm. long, flat, distichously branched, traversed by 
a flat immersed midrib ; the branches issue from the sharp edges, are flat, 
ribbed and pinnatifkl with strap-shaped falcate lobes or laciniae, 10 to 15 
cm. long and 12 mm. or so wide. There are no vesicles. Receptacles, 4 mm. 
long, moniliform when ripe, appearing on the opposing margins of the rachis 
and the laciniae sometimes making a long fringe. The hollowed con- 
ceptaeles are connected by a pore or canal with the surface, and are lined 
w^h long simple filaments (paranemata) , among which are found bright 
yellow small antheridia in racemes and narrow obovoid oospores. 
The colour is a dark olive-brown. The substance is firm and leathery, 
and the plant does not give off a slimy mucus when steeped in fresh water. 
A ictoria and South Australia east of Cape Northumberland ; and Tas- 
mania. Growing at no great depth in the Laminarian Zone. 
SCYTOTHALIA (Turner) Greville. 
As the characters of the genus were based on those of the single Aus- 
tralia n species, it will be sufficient to describe the species. 
