HEVISION OP THE NATUKAL ORDER HEDERACE^. 173 
this can well be confounded," did Mr. Turner confonnd them because 
they grew from the same root ? or is D, viridis or D. ligulata diflerent 
state or sexes of the same plant ? 
Dr. Greville and the younger Agardh consider D. viridh as a 
different genus, and the latter author characterizes the genus Di- 
chloria from Desmareslia, because it has an ecostate frond without any 
central canal • but this is a mistake, for Dr. Harvey, in his 'Phycologia 
Britannica,* t. 312, f. 2 and 3, figures the midrib and the central canal 
as Desmarestia viridis. 
JDesmarestia vii'idis looks very like a gigantic representation of the 
byssoid fibres that are developed on the margin of the frond of D. 
aculeata and D. ligulata^ when they are in a perfect state, and it 
chiefly differs from Desmarestia in not having such fibres developed on 
it at any period of its life. Can it be a gigantic development of this 
part from the root of the plant? 
EEVISION OF THE NATURAL ORDER HEDERACEM. 
m 
By Berthold Seemann, Ph.D., P.L.S. 
{^Continued from p, 81.) 
_ VI. On the Polypetalous Genera with several Distinct 
Styles. 
+ 
«h 
Under this heading are provisionally grouped together all those 
genera which, when the fruit is ripe, have several distinct, generally 
recurved styles, Gasto/tla, Grotefendia, and Nesopa)iax would have 
been inserted here, if I had not already treated of them under a pre- 
vious heading, I exclude Sciadodendron and TorlcelUa, which, accord- 
ing to my definition, do not belong to Hederacece, 
CONSPECTrS GENERUM HEDERACEARUM POLTPETALARUM 
STYLIS PLURIMIS (3-oo) DISlIiN^CTIS. 
XX. Gilibertia. Pedicelli inarticulati. Flores ecalyculati, her- 
maphroditi. Petala 5-9, ^libera. Stamina 5-9. Drupa baccata, 
5-7-pyrena. Albumen . . . — Arbores inermes Araericae australis 
troplcse, foliis exstipulatis simplicibus, umbellis compositis. 
