9 6 



convinced me thal plants of ./. Bowerbankii can have broad joints and stil! have nothing really 

 in common with A. canaliculata. A. anceps can also have broad joints at its base though not 

 nearly as broad as I have seen them in A. Bowerbankii. 



central strand has, just like the central strand of A. anceps, 2, 3, 4 rows of long 

 cells from 80 — 100 u long. These are foliowed by a row of shorter cells from 20 — 40 u. long, 

 and dien comes a row of ver\' short cells trom cS — 12 *j. long. The latter two rows are not 

 always developed, sometimes one finds only one row of ' 20 p. high. The cells of the central 

 strand spread fan-like from the centre towards the periphery; the cortical layer is thicker than 

 !. anceps, the conceptacula are often more or less overgrown and appear therefore smaller 

 than in A. anceps but they are really not smaller. As a rule they cover one side of the joint but 

 1 found them frequently on both sides. 



On PI. XIV are figured two nodes of Amphiroa Bowerbankii; fig. 17 shows us the 

 node in a young stage seen from above, fig. 16 in longitudinal section. On the same plate we 

 see a node of A. exilis and A. ephedraea and on PI. XVI, fig. 7 and 8 a node of A. anceps. 

 . I . exilis was not amongst the plants of the Siboga collection, but I thought it worth while 

 to have its node figured, because these four nodes show clearly how with small variations a 

 distinctly different node is formed. In A. anceps and A. Bowerbankii the node is formed of a 

 part of the central strand and a part of the cortical layer, in A. exilis the whole central strand 

 and a part of the cortical layer take part in the formation of the node, and in A. ephedraea 

 the notie is built up of the entire central strand and the entire cortical layer. In the marmer 

 in which the long and short cells alternate in these four species and in the fan-like spreading 

 of the cells from the centre towards the periphery, there is another indication of their close 

 relationship. All the above named four species occur on the East coast of South Africa and 

 at least three of them along the coast of New Holland and interveningf regions. 



6. Amphiroa ephedraea Lamck. PI. XIV, fig. 13. 



Corallina ephedraea Lamarck, Mem. du Mus. II, 18 10, p. 238. 



Amphiroa Gailloni Lamouroux, Pol. flex. t. XI, 18 16, p. 298. 



Amphiroa fusoides Lamouroux, Pol. flex. t. XI, 18 16, p. 298. 



Amphiroa ventricosa Lamouroux, Sec. Decaisne. 



Amphiroa ephedraea Lamarck, Harvey Nereis Austr. t. XXXIX, p. 95. 



Amphiroa Gueinzii Harvey, Nereis Australis, t. XXXIX, p. 95. 



Amphiroa Poppig'n Endlicher et Diesing. 



Amphiroa ephedraea Lamarck, Areschoug in J. G. Agardh, Spec. Gen. et Ord. Alg. 185 1, p. 534. 



Amphiroa ephedracea Decaisne, Kützing, Tab. Phyc. t. 8, tab. 47. 



Benkulen, Sumatra. de Bril. leg. Snackey. 



Sturdy plants, fronds branching dichotomously, branches spreading; joints at base of plant 



indrical or compressed; upper joints cylindrical or a little compressed, many times longer 



broad. Central strand consisting of 2, 3 rows of elongated cells from 60 — 118 tj. high, 



row of shorter cells from 20 — 40 u high, which again is foliowed by a row of 



from 8 — 12 <). high. Sometimes one finds only one row instead of two, which 



20 — 40 u. Node consists of entire central strand and cortical layer, which 



