ae = Ss inches long, setaceous. — Joints evident in all paren 
536 ALGH NOVA ZELANDIÆ. 
in the dichotomous filaments not being equal in diameter 
throughout, but their divisions gradually tapering to a fine 
point. The stem has 5 radiating tubes. 
53. Polysiphonia dendritica, Ag.; prona, ad algas majores ap- 
plicita pusilla disticha bipinnata, caule compresso pinnis 
creberrimis elongatis cum ramulis subulatis alternantibus 
obsesso, pinnis iterum pinnatis, pinnulis subulatis ap- 
proximatis alterne majoribus ramulosis et minoribus sim- 
plicibus, articulis brevissimis pluri-striatis, ceramidis sepe 
obliquis pinnulas terminantibus globoso-urceolatis ostiolo 
prominulo. 
Has. Parasitical on Gelidium lucidum. 
Frond 1 inch to 1 inch in length, lying flat on the surface 
of the Gelidium, and sometimes attached to it by the whole 
length of its main stem, all the branches being free. Agardh 
describes his plant (a native of Brazil) as being “ inordinate — 
ramosa, pinnis simplicibus compositisque intermixtis.” We 
consider this apparent, not real, irregularity of the branching - 
to have arisen from the frond at first being margined with 
subulate teeth which never change their form or size, but 
from whose axils spring secondary branches fringed like the — 
primary with subulate ramuli, and that again, in the axils * 3 
of these ramuli, tertiary branches are formed and so on. In 
this manner there arrives eventually a frond with simple and 
pinnated branches intermixed, and by the occasional non-  — 
development of the latter, irregularly so. This mode of - 
branching is similar to that of Polyzonia. : 
54. Polysiphonia aterrima, nobis; rigidula, atra, caule sulcato - : 
brevissime articulato basi nudo setaceo sursum decompo- 
site ramosissimo sensim attenuato vix dichotomo, ramis 
-alternis secundisve iterum et iterum alterne divisis cir- 
. eumscriptione obovatis, ramulis ultimis subulatis subsim- 
_plicibus distantibus erectis axillis apicibusque acutis, arti- — 
culis omnibus brevissimis 12-siphoniis, ceramidiiis ovato- — - 
globosis obtusissimis sessilibus sparsis. a 
Has. East Coast, Colenso. 
