366 
THE SEAWEEDS 
outer side of the ramelli. Cystocarps subterminal towards the apices, set 
in an involucre of ramelli. 
Tasmania (in the Tamar). 
Geramium fastigiatum Harvey. 
Frond 10 cm. to 20 cm. high, filiform, regular, irregularly dichotomous, 
fastigiate; the segments erect, patent, apices furcate, lower articulations 
longer than wide, upper interstices somewhat coloured. Tetrasporangia 
verticil late around the nodes, sometimes few outside the cortex, almost 
always glabrous. Cystocarps sessile on the segments, lateral; involucrate 
ramelli round the cystocarps slightly prominent, simple, sparse ; the colour / 
of the caespitose parts purplish, the ends bright red. Substance flaccid; 
does not adhere to paper. 
West Australia (Fremantle), Atlantic, and Mediterranean. 
Fig. 184 .— Ceramium fastigiatum : a, upper forks of a 
tetrasporic plant, showing form of apices, 
distribution of tetrasporangia in young nodes, 
and relative nodal development, x 50; t>, 
nodes from an older part, showing several 
emergent tetrasporangia, x c, naoit 01 
upper branching of a small portion of a tetra- 
sporangial plant, x 6; d, uppermost forkings, 
showing young cystocarps with involucral 
brancniets, x Z5; e, forked tip of the type 
with divergent apices, x 150; f, two nodes 
with cortication, from an old portion of the 
axis; g, type with incurved apices, node from 
a matured branch showing emergent tetra- 
sporangia with slight upgrowth of cells from 
below. (After Taylor.) 
