MARINE PHANEROGAMS OF THE ‘SEALARK’ EXPEDITION. 165 
CLADOPHORACEA. 
BoopuEa, G. Murr. & De Toni. 
9. BoopLEA vax Bosser, Reinb. Neue Chlorophye. Ind. Ocean, in Nuov. Notar. vol. xvi. 
(1905) p. 148. 
Coetivy, on reefs exposed at dead low tide. Cargados Carajos, 45 fms. 
Geogr. Distr. Malay Archipelago, ‘Siboga’ Expedition! Lucipara Islands, fide 
Reinbold. Mauritius, Ayres! in Herb. Kew. Seychelles, Dupont! in Herb. Kew. 
Diego Garcia, German Deep-sea Expedition, * Valdivia, 1898-9. 
The specimens of this plant collected by Mr. Gardiner vary slightly in the size of the 
filaments, but they all show the distinguishing character of the long slender unbranched 
unicellular rhizoids which arise from any part of the thallus, and each bears at the end 
a well-developed tenaculum. Major Reinbold very kindly examined our plants, and 
referred them at once to his Boodlea van Bossei. We do not figure the plant here, since 
we understand that Major Reinbold will figure and describe it more fully in his forth- 
coming account of some of the *Siboga' alge. Though we have examined a number of 
other specimens in the British Museum Herbarium, we do not find a single specimen 
of B. van Bosset. In the Kew Herbarium, however, there was one specimen from the 
Seychelles and another from Mauritius. 
During our search for B. van Bossei we found several hitherto unrecognised specimens 
of B. coacta, G. Murr. & De Toni, which we here take the opportunity of recording :— 
3. B. coacta, G. Murr. & De Toni, in Journ. Linn. Soc., Bot. xxv. (1889) p. 245, t. 49. 
Friendly Islands, Vavau, Harvey, no. 107 (sub “ Cladophora sp.") ! Friendly Islands, 
Lifuka, Harvey, no. 109 (sub ** Cladophora sp.")! Mauritius Arsenal, no. 78 (collector 
unknown), July 1868 (in Herb. Mus. Brit.)! Mauritius, Barkly Islands, Jan. 1870, 
` Colonel Pike, no. 148! 
Micropicryon, Decaisne. 
4. MICRODICTYON PSEUDOHAPTERON, sp. n. (Plate 22. figs. 1-4.) 
M. fronde ramellis radicantibus paucis substrato affixa, foliacea, e filamentis cylindricis 
primo opposite deinde stellatim ramosis inter sese reticulatim per pseudohaptera 
conjunetis composita. 
Amirante, 20-44 fms. and 30-100 fms. Saya de Malha, 25 and 26 fms. Cargados 
Carajos, 45 fms. 
The principal interest of this species lies in the fact that it diverges from the type of 
structure hitherto recognised as characteristic of Microdictyon. That genus, it will be 
remembered, consists of a network of short cylindrical cells situated in one plane only. 
Emerging on each side at the articulations of the main filaments, either singly at right 
angles to the main axis or in pairs at acute angles, the lateral branches with their 
branchlets come into contact with their neighbours and become attached to them, thus 
Producing square or polygonal meshes. The main articulated filaments may be seen 
Coursing like veins through this reticulated membrane. No true tenacula a hitherto 
C 
