14 ANTONY GEPP AND ETHEL S. GEPP. 
EXPLANATION OF PLATES I—IV. 
PLATE I. 
Lessonia grandifolia nob. Figs. 1a, 16. Mature fronds, showing flattened stipes dichotomously 
branched and usually twisted, bearing long, simple, flat fronds with undulate margins and broken apex ; 
jis natural size. Fig. 2. Three very young plants attached to a branch of Desmarestia harveyana, and 
exhibiting even at this early stage almost as much branching as is found in a mature plant; natural size. 
Fig. 3a. Transverse section (diagrammatic, and showing no cell-structure) of stipes at base of fig. la, 
showing concavo-convex form and rounded-obtuse margins; natural size. Fig. 3b. Transverse section 
of stipes, being the top of the cut branch on the left of fig. 1b, and showing two acute margins and 
a long, light-coloured intra-medullary band; natural size. Fig. 3c. Portion of same (about two-thirds 
of its width), showing that the intra-medullary band is composed of the cross-sections of scattered 
trumpet-hyphex ; the bulk of the section consists of medulla, limited on the outside by the indistinct 
subcortex and the pigmented cortical stratum. (x 10.) Fig. 4. The same in longitudinal section ; the 
medulla here is also indicated by the trumpet-hyphi, which appear as longitudinal streaks. (x 10.) 
PLATE II. 
Lessonia grandifolia (continued). Fig. 5a. Transverse section of mature lamina, representing one- 
half only of its thickness, and showing on the left the short, vertical rows of pigmented cortical cells ; 
beneath this is the subcortical stratum of about 2 rows of rotundate cells, which are twice as large as the 
cortical cells and pass into the closely packed hyphe which form the outermost portion of the medulla 
and appear here as round cells, but are shown to be hyphe in longitudinal section (compare fig. 7) ; 
these hyaline hyphe become more and more separated towards the middle of the medulla, and run in 
various directions through the gelatinoid matrix, and among them are shown a few ensheathed trumpet- 
hyphe. (x 110.) Fig. 5b. Small portion of similar section, showing four trumpet-hyphe with their 
sheaths of small cells and a few of the ordinary hyaline hyphe of the medulla. (Xx 450.) Fig. 6. 
Transverse section through a very young lamina (as in fig. 2), showing a monostromatic cortex of 
eranular coloured cells, a subcortical layer of 1-2 rows of large clear cells, and a medulla composed of a 
few lax hyphx and one ensheathed trumpet-hypha. (x 450.) Fig. 7. Longitudinal section of mature 
lamina representing half the thickness of the frond, and showing (as in fig. 5) the short vertical rows of 
pigmented cortical cells ; the subcortex of 1-2 rows of rotundate cells twice as large as the cortical cells ; 
and the medullary hyphe densely packed on the outer side and becoming gradually more laxly arranged 
towards the interior, where, interspersed among them, are portions of three trumpet-hyphe in longitudinal 
and one in transverse section. (x 110.) Fig. 8. Longitudinal section of very young frond, showing the 
three strata already described for fig. 6. (x 340.) Fig. 9. Portion of medulla of stipes in longitudinal 
section, showing a trumpet-hypha with its sheath of small cells and its wall densely marked with transverse 
striz ; the cell-contents have contracted into a narrow strand along the axis of the cell. (x 450.) 
Lessonia simulans sp.nov. Fig. 10. Outer part of a longitudinal section of stipes, representing the 
external part of the medulla, which is composed of densely packed straight hyphe ; these latter externally 
pass gradually into a pluristromatic subcortex of large round and transversely oblong cells which, running 
radially outwards towards the periphery, subdivide more and more, forming a cortex composed of short 
vertical rows of small quadrate cells. (x 110.) 
PLATE IIl. 
Desmarestia harveyana nob. Fig. 11. Small portion of a large plant, showing that the ramification 
is always opposite ; natural size. Fig. 12. Apex of an ultimate branchlet in surface view, showing that 
the cortex is continued to the very apex of the axial filament. (x 110.) Fig. 13a. Transverse section 
of a mature stem, showing its compressed form ; in the centre is the ensheathed primary axial filament and, 
ee 
