Ser. RuoposPeRMpa&. Fam. Spherococcoidea. 
Puate CCXLIV. 
DELESSERIA DENTICULATA, Zar. 
Gen. Cuar. Frond leaf-like, membranaceous, areolated, symmetrical, sim- 
ple or branched, midribbed. Fructification : 1, hemispherical eon- 
ceptacles, sessile on the midrib, or on a lateral nerve, containing a 
tuft of moniliform spore-threads on a basal placenta; 2, tripartite 
tetraspores, in definite sor or spots, on the frond, or on accessory 
leaflets.—-Drtesserta (4g.), in honour of Baron Delessert, a distin- 
guished patron of botany. 
Frons foliacea, membranacea, areolata, symmetrica, simplex v. ramosa, costata. 
Fruct.: 1, coccidia in costa venisque frondis sessilia, hemispherica, fila spori- 
fera moniliformia a placenta basali emissa foventia: 2, tetraspore triangule 
divise, in soros definitos collecta. 
Detusserta denticulata; frond ribbed, dichotomous, rather rigid; seg- 
ments broadly linear, curled and wavy, with a sharply-toothed mar- 
gin; rib opaque, cartilaginous, vanishing beneath the apex; mem- 
brane formed of bluntly-hexagonal cellules; veins none; sori in 
obovate, fimbriato-dentate fruit-leaves springing from the midrib. 
D. denticulata; fronde costata dichotoma rigidiuscula ; laciniis lato-linearibus 
erispato-undulatis margine denticulatis ; costa opaca cartilaginea apicem ver- 
sus evanescente ; membrana cellulis parvis rotundato-hexagonis ; venis nullis ; 
soris in sporophyllis obovatis fimbriatis e costa prorumpentibus. 
DeELEssERIA denticulata, Harv. in Trans. R. I. Acad. v. 22. p. 548. Harv. 
Alg. Austr. Hxsic. n. 274. 
Has. Rottnest Island, W. Australia, rare, W. H. H. 
GroGcr. Distr. Western Australia. 
Descr. Root discoid. Stipes 2-3 inches long, cartilaginous, more or less winged 
with membrane, branching at the summit, and continued as the midrib of 
several irregularly dichotomous or alternately subdivided, sometimes pinna- 
tifid fronds. Segments broadly linear, very obtuse, patent, all traversed by 
midribs which become obsolete just under the apices, sharply and unequally 
toothed along the margin, curled and wavy. Conceptacles unknown. Sori 
of tetraspores lodged in minute, obovate, lacerate or fringed fruit-leaves, 
which spring from the midribs of the younger segments. The colour is a 
clear, but not very brilliant red, which darkens a little in drying. The sud- 
stance is rigid, though the membrane is formed of but a single stratum of 
cells, and in drying the frond scarcely adheres to paper. 
In the ramification of this species there is some resemblance 
