i
leô
ULVA FÜRFUKACEA.
Minute Ulva.
C l a s s a n d Obdeb CRYPTOGAMIA ALGÆ, ü « « . _ N a t . Obd. ALGÆ, Juss.
G EN E R IC CHARACTER.
Frons plana, membrana æquali. Sporidia minutissima subquaternata.—AaAROH.
Fro n d plane, the membrane equal. Sporidia (or minute granules) very
minute, subquaternate.
S P E C IF IC CHABAC TER .
U lva fu rfu ra c e a ; frondibus minutissimis obovato-rotundatis, erecfiusculis, coes-
pitoso-effusis.
U. fronds very minute, roundish obovate, suberect, tufted and effused.
U lva fu rfu ra c ea , Fl. Dan. t. \ m — Lyngb. Hydroph. p. 32.—Ag. Syn. p. 43.
Syst. Alg. p. 190.
H ab On the surface of wood in shady places, and also on stone. Appin,
Captain C a rm ic h a e l. I t has been found in Fn g lan d on the walls of
King’s College, Cambridge, by my acute friend M. B e r k e l e y , Fsq.
Plant producing a green furfuraceous crust. Fronds scarcely a line long er
broad, very numerous, tufted, somewhat erect, o f an obovate or roundish
form attached by a very minute base; margin entire, undivided or
somewhat lobed, more or less inflexed either at the sides or apex, or
both. Substance delicate, composed of a very thin fine uniform membrane,
bearing a prodigious number of roundish granules, often arranged
in symmetrical square masses, o f about 16 granules each;
the membrane between tbe squares resembles pellucid lines passing
across the whole frond, and intersecting each other at rig h t angles.
Sometimes the squares o f granules are more uneq u a l; sometimes solitary
ones are formed of 4 granules only ; at others, again, a great part
of the frond is nearly occupied by one dense mass.
The great similarity of structure between this plant and
Bangia calophylla, Carm. (t. 220.), and also Scytosyphon ve-
lutinus, L y n g b . was remarked by Mr B e r k e l e y , who had
the kindness to communicate to me a share of the specimens
he alone has hitherto had the good fortune to discover in Eng