Schizothrix] \\. \ lginarie b (Wi 
dissepiments, and in the cells never being short* c than the di 
as well as in its subsolitary Eree-ewimming habit 
2. PORPHYROSIPHON K .... (1850 52). 
I. P. Notarisii Ciitz. Tab. Phyc. ii. (1850 2), 7. • 27, f. u; R 
el <i. s. West, in Journ. Bot. 1897, p. 271. 
This interesting and characteristic alga appears to have been 
abundant in the district traversed by Welwitsch. 
IVm.ii Am»i\i.u. Alga ti-iTi'stris, latissimas palustrinm terrarum 
plagas colore sangnineo ferrngineo tingens, prope Condo March 1857 
No. 9. Alga caespitosa, glauoo riridis, inter mnscorum ca spites in 
cryptis editiornm montis de Cazella crescens ; Dec. 1856 wo, 107 
(These specimens appear to be old ones; many of the sheathe were 
empty, and the red colour lias mostly disappeared.) 
Hi n i. \. In udia Bylvaticis et apricis inter Moninoet lac. [vantala 
latas plagas colore fusco-sanguineo obducens : April I860. No. 14. 
Preqnens in pascnis pluv. autnmnalibus rrequentiua inundatis, demnm 
exsiccantibns, ad lacum magnum de [vantala; March l--''. 11 - \ 17 
and 18. " Alga terrestris, atro- vel fusco-sanguinea, late ca 
casspitibus lubricis planis e filamentia tenacious dense intertextis el 
conteztis versus marginem radiantibus conflatis, terra arete adhaerenti 
litis: loca, ubi freqiiens ohvia lia-c Alga, tempore spon^iosa facta inultis 
aliis stirpibuB oliginosis solum prabent." 
This Alga occasionally branches : these branches are few and of th. 
same thickness as the primary filament, around which they are i losely 
coded. The sheath of t h< • branch becomes solid at the base, and 1- 
gradually merged into that of the primary filament, its trichome not 
being iii any way connected with that of the latter. The branching 
really consists of a close application of the base of one filament to the 
sheath of another, the fusion being for such a short distance that the 
two trichomas are never present within the same sheath. 1 
the same type as the branching present in Schizothrix, but the division 
into branches is deeper, causing the branches and primary filaments b 
be of equal thickness. The above remarks prove that Porpkyrosiphoii 
is very closely related to Schizothrix, and emphasizes its position in the 
Vaginariece. This affinity was inferred by Gomont (in Ann. Sci. Nat. 
7 s, tie, Bot. w. 332) from a consideration of an entirely differenl 
character, viz. the structure of the sheath. Gomont's statement on th 
same page that Porphyrosiphon has no branches is. however, • n 
:;. POLYCHLAMYDUM W.et <;.S. W.-s, in Journ. Bot, 
p. 271. 
1. P.insigne W. ot G.S. Wesl in Journ. Bot. 1897, p. 271, 
f. 1,2. 
Loanda. — Ad Nitellam et Najadi in lacu de Qnifandongo 
De,-. 1853. No. 195. 
The peculiar sheaths of this genus readily distinguish it from the 
other genera of the Vaginariea:, its nearest ally being Da yglaa Thw . 
from which it differs in the very firm multitubular sheath with an 
open apex, and in the much thicker trichomas with very much shorter 
■ •ells. There is a very distinct line of demai reen the innei 
and outer constituents of the sheath, th< onto rmosi one being rendered 
conspicuous only by the • straneoua material adhering to it. Th< 
trichomas are also usually without any interruption for a considerable 
lensrth. 
