264 Dansk Botanisk Arkiv, Bd. 3. Nr. 1. 



pericentral cells, and from fig. 258 E it is seen that each of these 

 cells bears 3—4 antheridia. 



Of cystocarps I have only found some few, of which one is 

 figured in fig. 257 B. 



This species occurs especially in shallow water and in shel- 

 tered places, but it may also be met with in somewhat more 

 open localities. In sheltered places, e. g. in the lagoons, where it 

 is a common and characteristic species in the communities of 

 algæ which grow upon the roots of the mangroves, the form of 

 the plant is more slender, the ramuli are placed at greater intervals 

 and bear fewer spines, and the colour of the plant is often darker. 

 In the lagoons and in sheltered places it often occurs also lying 

 loose upon the bottom, forming entangled masses together with 

 other algæ. 



In the more open and exposed localities the plant is more 

 robust. 



Acanthophora spicifera has been found with tetraspores, an- 

 theridia and cystocarps in the months of January — March. 



It is a very common species on the shores of the islands. 

 Geogr. Distrib.: West Indies, Brazil, Biarritz. 



2. Acanthophora muscoides (L.) Bory. 



BoRY DE St. Vincent in Duperrey, Voyage autour du Monde, Bota- 

 nique, Cryptogamie 1828, p. 156. J. Agardh, Spec. Alg., p. 816. Kützing, 

 Fr., Spec. Alg., p. 859. Tabulæ Phycol. vol. XV, tab. 77. Falkenberg, P., 

 Rhodomelaceen, p. 230. Okamura, Icones. Jap. Alg., vol. I, pi. 8, figs. 

 8—10. 



Fucus muscoides L., Spec. Plant., 1753, p. 1161; 1763, p. 1630. 



Chondria muscoides Ag., Spec. Alg., p. 361. 



Acanthophora militaris Lamour. Essai Thalassiophytes in Ann, du Mu- 

 seum, vol. 20, 1813, p. 132. 



Acanthophora Delilei Harv., Nereis Bor.- Am., II, p. 18. 



The few specimens found are small, about 6 — 7 cm high. 

 Like the preceding species, the present one is fastened to- the 

 substratum by means of a flat disc, from which several erect 

 shoots grow upwards. The ramification is more developed, and 

 the plants form more dense bushes than those of Acanthophora 

 spicifera. 



Acanthophora muscoides belongs together with A. Delilei to 

 the group of species, in which now and then isolated spines are 

 found upon the main stem, and the branches issue from the cor- 



