12 Dansk Botanisk Arkiv, Bd. 2. Nr. 2. 



present species is also different from the shorter, conical-piriform 

 ones of Eet. Hincksiæ. The size of the plurilocular sporangia is 

 more variable in E. coniferus and the larger ones exceed in size 

 those in Ectoc. Hincksiæ. 



The unilocular sporangia have only been found solitary in 

 the axils of the branches while in E. Hincksiæ many occur 

 together in a row along the upper side of the branch, and the 

 involucre often found here (compare Sauvageau 1. c, and my 

 remarks in The Marine Algæ of the Færoes, Botany of the Færoes, 

 Part II, 1902, p. 412) has never been found in the West Indian 

 plant. 



In "Alg. Novara", p. 45 Gkunow described a var. aiistralis of 

 Eet. Hincksiæ in which the ends of the ramuli sometimes ended in 

 long hairs showing in this respect a likeness to the present plant. 



After the above was written I received from Professor Kuck- 

 uck (to whom I had sent a preparation of my plant) some 

 drawings of his of Ectocarpus irregularis Kütz. and having seen 

 these I saw at once that my plant was very nearly related to 

 this species of Kützing being perhaps merely a form of it. 

 Nevertheless some differences are present and as it comes from 

 quite another geographical region to Kützing's plant (which is found 

 in the Adriatic Sea) I think it justifiable to keep it as a full 

 species. Judging from the very beautiful and instructive figures 

 which Professor Kuckuck most kindly allowed me to see, and 

 further from the rather incomplete description found in the 

 literature, the Adriatic plant seems to be somewhat smaller in 

 all respects to the West Indian. This also Prof. Kuckuck 

 pointed out in his letter to me. 



Further in the West Indian plant the plurilocular sporangia 

 are found upon the upper side of the branches and nearly always 

 in the corner between these and the main filaments only rarely 

 do they occur upon the main filaments. 



In the Adriatic alga, judging from the drawings of Prof. 

 Kuckuck, the sporangia seem to occur much more irregularly, 

 very often upon the main filaments, sometimes even quite below 

 the branches and also not so strictly confined to the upper side 

 as in my plant, which just in this respect shows likeness with 

 Ectocarpus Hincksiæ. 



I may further add that when determining my plant I tried 

 to refer it to Ectocarpus irregularis but the very misleading 

 figure of Kützing ("Tab. Phycolog.", vol. 5, fig. 62) led me to 

 give up the idea. 



