MARINE ALG. 5) 
nigrescens, and L, littoralis; and even in L. ovata the “ Trichter” (as Grabendérfer 
calls them) differ in being more inflated at their funnel-shaped ends and quite 
destitute of a special sheath. 
In the very young lamina (J in. long), the structure is much simplified (fig. 6). 
The cortical cells are crowded, and obscured by coloured granules and form a mono- 
stromatic layer, beneath which is the subcortical stratum of about 2 rows of large cells, 
round in transverse section, or sometimes twice as long as broad in longitudinal section 
of lamina (fig. 8). In the middle les the medulla, consisting of some three or more 
rows of longitudinal or transverse hyaline hyphe ; among them are very few trumpet- 
hyphee, each in its sheath. 
As to the structure of the stipes, it is im the main similar to that of the mature 
lamina, but the cortex is a little thicker and more deeply coloured, the medulla is 
far thicker and the sub-cortical layer much less distinct. In a transverse section 
there is a narrow, more opaque, median band stretching right across, along the widest 
diameter, distinctly visible to the naked eye (fig. 3b). This, under a low power of the 
microscope, is seen to contain dots and streaks (fig. 3c, and 4), which, under a higher 
power, are seen to be trumpet-hyphe in transverse and longitudinal section (fig. 9). 
The structure of the basal holdfasts is simple, the main tissue being composed of 
thin hyaline hyphe mainly longitudinal, most of them exhibiting a contracted globose 
mass of coloured protoplasm ; this tissue contains no ensheathed trumpet-hyphze and 
passes gradually through a cell-like subcortex to a submonostromatic cortex of small 
cells obscured by coloured granules. 
Neither stem nor lamina possess any lacune like those that characterise L. 
nigrescens and other species. 
L. grandifolia resembles our L. simulans in external habit, but differs in structure, 
as we show under that species. It also approaches LZ. laminarioides in habit, but 
differs from it in being 10-20 times as large, in having the stems flat and twisted, and 
the medullary hyphe interspersed with the ensheathed trumpet-hyphe mentioned 
above. J. ovata, though, as we have said, possessing trumpet-hyphe somewhat like 
those of our plant, is otherwise very different, having small oval lamin less than 
20 em. long, and a stem which, according to Grabendorfer (op. cit., p. 643), may attain 
a leneth of several metres and a thickness of about 10 cm. 
3. LESSONIA SIMULANS. 
(Plate II., fig. 16.) 
L. simulans Gepp, Journal of Botany, 1906, p. 425. 
L. grandifolia, pro parte Gepp, op. cit., 1905, p. 105, tab. 470, fig. 6. 
Planta incompleta. Frons laminarioidea ut in L. grandifolia, stipite complanato 
ancipite suffulta simplex, lanceolato-linearis, longa, lata (12°5 em. plusve) marginibus 
integerrimis. Laminae substantia pergamentacea vel coriacea e stratis tribus com- 
posita ; cellulis corticalibus monostromaticis quadratis eranuloso-obscuris ; subcorti- 
to) 
