142 
CLASS IL— ORDER 111. 
ing Tot the polypus or constructor of this stony habita- 
tion. 
Their colour is the same as that of the Corallinas, 
either fresh or in a dried state. 
They are found on the Thalassiophytes of the va- 
rious seas, generally on the same species. 
MEMBRANOUS. 
1. Melobesia memhranacea. Patches very thin, 
nearly orbicular ; some projecting cells in the centre, 
but invisible to the naked eye. 
On the marine plants of the western coast of 
France. 
PUSTULATED. 
2. Melobesia pmtulata . Patches round, and 
raised as if embossed ; cells visible to the naked eye, 
and projecting. Plate 12. fig. 2. a. B. 
On the marine plants of the French coast. 
MEALY. 
3. Melobesia farinosa . Patches of various shapes, 
and very thin, in general extremely small, and giving 
a white dusty appearance to the leaves of the Fu- 
ci ; cells invisible to the naked eye, placed on the 
summit of small projections. Plate 12. fig. 3. 
Very abundant on the Fucus linifolius. 
. 
WARTY. 
4. Melobesia verrucata. Patches fragile, with 
uneven surfaces ; cells placed on the top of small 
elevations in the form of warts. 
On the Fucus of the Mediterranean. 
