IOI 



Almost the same structure occurs also in an alga in Surixgar's herbarium called A. pertianae 

 Aresch. I have not been able to find the diagnosis of Areschoug for A. peruanac. Perhaps it 

 is only a herbarium name and therefore without value. My specimen is barren but the plant 

 is so sturdy that I must leave it to others to decide whether this plant is a separate species 

 or a variety of A. Beauvoisii. It differs in the structure of its node so far as this, that it is 

 very distinctly semMunar. 



To A. rigida Ardissone refers : 



A. spina Kütz. 



A. irregularis Kütz. 



A. amethystina Zan. 



A. cladoniacformis Men. 

 I have not seen A. amethystina Zan. but the three others named pseudo-species had 

 all the same structure of node as the typical A. rigida. This same structure of joint and node 

 occurs also in a specimen in the herbarium of Prof. Süringar which was collected by him in the 

 West Indies. It is characterized by widely spreading, dichotomous, intricate branches and may 

 well be distinguished as f. divaricata pi. XVI, fig. 13. I have not seen a single type specimen 

 of A. parthaiopca Zan. and cannot decide whether it is a synonym of A. rigida as Bornet, 

 or of A. complanata (exilis) as Solms-Laubach affirms. 



A. verrucosa was described by Kützing in 1843 in his Phycologia generalis; he changed 

 this name afterwards into vcrruculosa, probably because the name of verrucosa had already been 

 given by Lamouroux to a species of Amphiroa. We shall however see in the following pages 

 that Amphiroa verrucosa Lamx. is not an Amphiroa, and therefore the old name of Kützing 

 may be revived. Solms-Laubach has described A. verrucosa (verruculosa) Kützing and A. 

 cryptarthrodia Zan. as two distinct species. They have however exactly the same structure of 

 joint and node and I consider them therefore as identical. A. verrucosa Kütz. as being the 

 older name, must be maintained. 



Though I have not seen A. valonioides Yenclo, the node of this alra is so well fio-ured 

 by Yendo that I was able to classify it in this key. I have neither seen A. zonata Yendo, A. 

 cchigoensis Yendo nor A. pusilla Yendo. According to the figures they seem to belong all three 

 to the genus Amphiroa and to stand near to A. Beauvoisii and A. pertianae, but as Yendo 

 has not given a figure of the node, I do not dare to express myself with greater certainty. 

 Amphiroa misakiense Yendo is probably an Arthrocardia. 



Metagoniolithon n. g. 

 PI. XV, fig. 9-14- 



The genus Metagoniolithon though it was not found in the collection of the Siboga 

 Expedition may well be treated here, for my researches on the Amphiroac of the Siboga led 

 me to create this genus. It has been characterized in the Synoptical Key on p. 86. It is 

 distinguished from Amphiroa as we have already seen by the anatomical structure of the 

 joint and node. The cells are of a uniform size throughout the whole joint, only growing 



