Caulacanthus.~\ 
IX. ALGjE. 
689 
setaceous, forming broad tufts, rigid, irregularly excessively branched; 
branches very spreading, simple or forked, set with horizontal, often secund 
spinous branchlets. — J. Ag. Sp. Alg. ii. 434. Rhodomela 1 spinella, Hook. f. 
and Harv. in Lond. Journ. Bot. iv. 534. 
Common on all the shores, on Corallines, shells, etc., Colenso. 
63. HYPNEA, Lamouroux. 
Frond pink or dull purplish, filiform, much branched ; branchlets subu- 
late, cartilaginous ; axis fibrous or cellular, dense, surrounded by several series 
of colourless polygonal cells, which decrease externally, outer series minute, 
coloured. Conceptacles sessile or immersed, thick-walled, containing stalked 
spores attached to filaments. Tetraspores zoned, sunk in the surface of 
swollen branchlets. 
Natives of both temperate zone9. 
1. H. musciformis, Lamour.; — FI. N. Z. ii. 244. Frond tufted, 
dark green and purple, excessively branched, 4-6 in. high ; branches filiform, 
incurved, thickened at the tips ; branchlets spreading, sporiferous, pod-like, 
lanceolate, beaked ; those bearing the conceptacles with divaricating spinescent 
divisions. — J. Ag. Sp. Alg. ii. 442. 
New Zealand, Banks and Solander. (N. S. and tropical Atlantic, Indian Ocean, Pacific, 
Australia.) — I have seen no N. Z. specimens. 
2. H. ? multicorius, Mont. Voy. au F6le Sud, 152. t. 9. /. 1; — FI. 
Antarct. 187. Frond 2-3 in. long, compressed, excessively corymbosely 
branched, ultimate branchlets subdistichous, alternate or subsecund, forked ; 
branchlets spreading, recurved, hooked. Fruits in the thickened tips of the 
hooked branchlets.— Rhodomela, Mont. 
Lord Auckland’s group, D’Urville. 
64. PTEROCLADIA, J. Agardh. 
Frond red, linear, flat, 2-edged ; midrib strong or indistinct, pinnate ; 
structure of 3 strata ; medullary of densely packed longitudinal fibres ; inter- 
mediate of larger roundish cells ; cortical of moniliform rows of coloured 
minute cells vertically placed. Conceptacles tliick-walled, hemispherical, 1- 
locular, on one surface. of the frond, containing obovate stalked spores; 
spores inserted on a parietal receptacle which is united to the pericarp by 
delicate filaments. Tetraspores cruciate, forming sori on dilated branchlets. 
Differs from Gelidium in the 1 -celled conceptacle. 
1. P. lucida, J. Agardh FI. N . Z. ii. 244. Root branching. Frond 
extremely variable, 6-18 in. long, red-purple, in. broad, pinnately de- 
compound, variable in breadth and branching ; often proliferous ; pinnules 
thin, flat, long or short and crisped ; midrib strong or faint. — J. Ag. Sp. Alg. 
ii. 483. Gelidium, Sond. ; Fucus, Br. in Turn. Hist. t. 238. 
Common throughout the islands. (W. aud S.W. Australia.) 
