308 
THE SEAWEEDS 
Subfamily Dasyeae (Kutzing) Schmitz and Falkenberg. 
THURETIA Decaisne. 
Frond stipitate; stipes filiform, inarticulate, branched; the branches 
bearing pinnatifid, compressed or flattened, midribbed and penninerved 
networks, formed of confervoid, anastomosing ramelli. Cystocarps urceo- 
late, springing from the midribs of the network, and containing a tuft of 
pear-shaped spores. Stichidia subglobose, sessile on the lateral nerves of 
the network, containing tripartite tetraspores. 
Thuretia querci folia Decaisne. 
Network flattened, linear oblong, lobed or subpinnatifid ; the lobes 
broadly oblong, obtuse, fimbriato-dentate ; articulations about twice as long 
as broad. Cystocarps much accumulated. Attachment discoid. Stems 
many from the same base, filiform, cartilaginous, elongate, often spirally 
coiled round each other, or so interwoven as to be inextricable, naked below 
Fig. 147 . — Thuretia quercifolia : a, summer 
frond; b, fragment of winter frond, 
bearing tetraspores; c, apex of an 
old network, with stichidia on the 
lateral nerves; d, small portion of a 
nerve with its stichidia, denuded; 
e, tetraspore; f, ceramidium; g, 
spores; h, fragment of the net. 
(After Harvey.) 
