No. 2] NEW SPECIES OR FORMS OF MELOBESIEAE. 9 


Melobesia (Heteroderma) coronata Rosan. 
Melob. p. 64. 
f. zonata Fosl. mscr. 
Thallus forming orbicular or slg doen concentric zonated 
crusts on Lenormandia. Conceptacles subconical or conical, partly 
150—200 p#, partly 250—300 yp in diameter seen from above. 
According to a young authentic specimen of MW. coronata in 
my collection, the above plant appears to be so nearly related to 
the said species that it scarcely may be considered more than a 
form of it. The species is as yet but little known, especially with 
regard to tendency of variation, and I do not yet exactly know 
its structure. The form zonata differs in the surface being more 
or less distinctly concentric zonate, and the crust somewhat thicker. 
Besides, according to Rosanoff’s description |. c. the basal cells 
seem to be a little shorter in the said form than in the typical one, 
and often with thicker walls. On a cross section of f. zonata the 
cells are frequently square or rounded, about 6—12 p in diameter, 
now however with the longest diameter in horizontal now in vertical 
direction. The crust consists in the peripherical portions of a single 
layer of cells with rather small cortical ones. It becoms thicker 
towards the centre, where it is composed of at least up to four 
layers of cells, perhaps even more in older crusts than that exa- . 
mined by me. 
There are to be found two kinds of conceptacles. A few-ones 
examined were empty. The one kind, the largest conceptacles, 
are conical or nearly so, 250—300 yp in diameter seen from above 
and probably identic with the cystocarpic ones described by Ro- 
sanoffl.c. ‘The other and smaller conceptacles are subconical, 
150—200 p» in diameter seen from above, being however uncertain 
whether those of sporangia or perhaps antheridia. 
The form in question is attached to Lenormandia spectabils, 
here forming solitary crusts up to nearly 1 cm. in diameter, or 
frequently smaller ones which partly anastomose. 
Occurrence. Hitherto only known from Port Elliot, South 
Australia, collected by Miss Brumsert and kindly communicated 
to me by Mr. Reinbold. 
