— 129 — 



Caulerpa Yickersii nov. spec. 



Caulerpa ambigua Vickers, Phycologia Barbadensis, Pl. XXXVII. Col- 

 lins, The green Algæ of North America (Tufts College Studies, vol. II, Nr. 3. 

 1909, p. 421). Okamura, On the Algæ from Ogasawara-jima (Bonin Islands), 

 Bot. Magazine, Tokyo, Vol XI, 1879 ex parte? 



Caulerpa nana frondibus a surculo repente, plus minus distincto 

 et irregulariter curvato, erectiusculis , teretibus, superne rarnulis 

 præditis; ramulis, fere cylindricis, distichis vel interdum perpaucis 

 irregulariter insertis, oppositis vel 

 alternatis, majoribus apice sæpe 

 furcatis. 



When examining my Bryopsis- 

 material I found this nice, small Cau- 

 lerpa growing entangled in a large 

 Bryopsis-tuît. The specimens met 

 with quite agree with those found 

 first in the West Indies by M lle 

 Vickers at Barbadoes and so well 

 pictured in her „Phycologia". M lle 

 Vickers has referred our plant to 

 G. ambigua Okamura and I agree 

 with her, that this is most probably 

 right but only in part. Whilst, na- 

 mely, our plant seems to agree with, 

 or in any case to come very near 

 to, that form figured by Okamura, 

 1. c, on pl. 1, figs. 7, 8, 9, 10, it 

 seems to be rather different from 

 that shown in figs. 3, 4, 5, 6. To 

 be sure Okamura considers these 

 two forms as belonging to the same 

 species, but I cannot help having some doubt in this matter and my 

 West-Indian material, in any case, seems only to come near to 

 the first mentioned form. 



I shall now give a description of the West Indian plant. 



As mentioned above, the plant was found growing in tufts of 

 Bryopsis and it was therefore also rather difficult to get the plant 

 separated out; most often at the base of the erect axes only some 

 few rhizoids were present, quite in accordance with what Okamura 

 has found in his plant. But afterwards I also found plants with 

 a part of the rhizomes, shorter or longer, most often very irregu- 



Botanisk Tidsskrift. 31. Bind. 9 



Fig. 2. Caulerpa Vickersii nov. spec. 



From Cruz Bay, St. Jan. About 6:1. 



