i 
: 
508 MR W. WEST AND MB G. S. WEST ON : 
cells (rarely of more), and the families are joined into large colonies by irregular 
mucous strands. Two of the families of cells with the mucous strand for attachment 
to the rest of the colony are shown on PI. 6, figs 8 and 9. A characteristic feature of 
the colony, and one by which this species can always be recognised, is the projection 
of the cuneate cells all round the margin. This is well shown in the photograph of a 
small colony on Pl. 4, No. 4. 
Actinobotrys, gen. n. 
Cellule in coloniis mucosis parvis associatze, subcylindrice, oblong, oblongo- 
ellipticee vel subglobosze, radiatim vel subradiatim (demum subirregulariter) disposite ; 
seriebus radiosis cellularum irregulariter et spurie subramosis; chromatophoris 
parietalibus singulis, cum marginibus irregulariter lobatis, pyrenoidibus nullis. 
44, A. confertus, sp. unica (Pl. 6, figs. 17-19). 
Cellule confertim radiantes, plerumque oblongo-elliptice, cum axibus longioribus 
radiatim dispositze ; colonize e cellulis 20-110 (circiter) formatee. 
Long. cell. 6-8°7 » ; lat. cell. 4°5-5°8 4 ; diam. colon. 43-65 wu. 
Hab.—Lochs Bairness, na Criche, Gorma, and Morar, Inverness ; Lochs Fadaghoda 
and an Seath, Lewis ; and Lochs Diracleet and Laxadale, Harris, Outer Hebrides. 
This alga occurred in quantity in some of the lakes examined, and was also observed 
from some of the bogs of Sutherland. 
The colonies are somewhat small, and they are enveloped in a more or less globular 
mass of mucilage sufficient to inclose the entire colony, but which is only rendered con- 
spicuous by staining. The cells are small, oblong-cylindrical or oblong-elliptic in shape, 
and are arranged in series (of from 4 to 7 cells each) radiating from the centre of the 
colony. ‘These series are often irregular, and commonly exhibit a trace of branching. 
The long axes of the cells are disposed radially, and there is generally a diminution in 
the size of the cells from within outwards, the outermost cell being not merely the 
smallest, but also more globular in shape. 
The chloroplast is solitary and parietal, generally with lobed margins, and is quite 
destitute of a pyrenoid. 
The genus stands near to Dictyocystis, Lagerh., but differs in the more crowded 
cells, which are rather smaller towards the exterior of the colony, and in the parietal 
chloroplasts. In Ductyocystis the chloroplasts are axile and substellate, with a central 
pyzenoid, but no pyrenoid is present in the parietal chloroplast of Actinobotrys. 
