93 



The different aspects which this Amphiroa can assume, have already been spoken of 

 in the beginning of this paper. On account of its variability it is not an easily recognized 

 plant. lts central strand and manner of forming the node have much resemblance to the central 

 strand and node of young specimens of A. fragilissima, still both are easily recognized if 

 carefully studied. A. foliacea has a strong tendency to flatten its frond and to form an undulating 

 border, visible even in almost cylindrical joints. The joints are thick throughuut their whole length 

 and lack the pad-like swellings at top and base that characterize older joints of A. fragilissima. 

 The half-immersed conceptacula, not nearly so prominent as in A. fragilissima, help further 

 to distinguish this species. 



A. foliacea is a widely spread plant-, it can grow so sturdy as to resemble outwardly 

 Metagoniolithon charoides (Amphiroa charoides) and I got it even under that name from the 

 West Indies. A longitudinal section through both plants will however show at once how widely 

 different they are. 



The different aspects A. foliacea can assume may be characterized as follows : 



f. procitmbens. PI. XIV, fig. i. 



fronds creeping, joints broad, winged with undulating border. 



f. erecta. PI. XIV, fig. 2—8. 



fronds erect, joints slightly winged, sometimes almost cylindrical. This latter form is 

 identical with the alga named A. nobilis Kütz. by Hauck in: Über einige von Hildebrandt 

 im Rothen Meere und Indischen Ocean gesammelten Algen. 



Grunow again in his paper on the ''Algen der Fidschi, Tonga und Samoa Insein" speaks 

 of an Amphiroa from Ovalau "bei welcher einige Aeste und Glieder sehr an A. tribulus 

 andere aber durch die langgliederige, oft fast stielrunde dunne Gestalt sehr an A. fragilis 

 erinnern". I think that this plant is A. foliacea, the more so because I found in the Herbarium 

 of the Hamburg Museum A. foliacea under the name of A. sq nar rosa Grunow. 



4. Amphiroa anccps (Lamk.) Decne. PI. XVI, fig. 6 — 8. 



Corallina anccps Lamarck, Mém. du Mus. II, 18 10. 



Corallina dilatata Lamouroux, Hist. des polyp. flexibles. Caen, 1 S 16. 



Amphiroa Karstalskii Postels et Ruprecht, 111. Alg. Oc. Pacifici 1840, at Bot. Mus. in herb. 



Petersburg. 

 Amphiroa Cumingii Postels et Ruprecht, 111. Alg. Oc. Pacifici 1840. 

 Amphiroa anccps Decaisne, Ann. des sciences nat. 1842. Bot., v. 2. 



Amphiroa nobilis Kutzing, Spec. Alg. 1849. Tab. Phye. t. 8, p. 25, pi. 51 in herb. Kützing. 

 Amphiroa dilatata Lamouroux, Areschoug in Agardh, Spec. Gen. et Ord. Alg. 185 1. 

 Amphiroa galaxauroides Sonder, Plantae Preiss. vol. 2, p. 188 in herb. Kützing. 

 Amphiroa ephedraea in Harvey, New South Wales Algae N°. 458! 

 Amphiroa ? in Ferguson, Ceylon Algae N". 119! 224! 442! 



Stat. 33. Pidjot Bay, Island Lombok. 

 Stat. 307. Bay of Endeh, Island Flores. 

 Sikka, Flores. leg. A. Weber-van Bosse 188S. 

 Southcoast Java, leg. Teysman. 



