ON THE GENERA ANADYOMENE AND MICRODICTYON. 45 
the approval of botanists, or I should not give to it the generic name 
of Grayemma, which, at the suggestion of Mr. Bennett, I propose to 
do,—that being a combination of the two names of my wife, who has 
been my companion and helper in all my studies for forty years, and 
who has some claims to be regarded as a botanist, as for several years 
she has studied seaweeds not only in the herbarium but in the living 
state, and has acquired such a knowledge of them that the late Sir 
W. Hooker entrusted her to arrange the British 4/ge in the Kew col- 
lection ; and Mr. Bennett, first to arrange the British, and then the 
general collection of Ælgæ in the Herbarium of the British Museum. 
The combination of the two names asa generic one is almost a novelty, 
but it appears to me that the termination of -emma is as pleasant-sound- 
ing as the usual diminutive of -e//a, and in this case more determinative. 
The name of Grayia has been already used in honour of Professor Asa 
Gray. 
SYNOPSIS OF THE GENERA. 
Genus 1. CALOMENA.—-Filament of frond formed of linear joints, fur- 
cately-branched to the end of the frond; disk of the frond minutely 
cellular. 
Genus 2. ANADYOMENE.—Filament of the frond formed of ovate 
cells with diverging cells on the tip, some of which are proliferous, and 
with cells on the sides; the disk of the frond with regularly dis- 
posed small ceils. 
Genus 3. Grayemma.—Midrib of the frond formed of several 
parallel series of cells, the terminal bearing radiated cells on their tip, 
and the disk of the frond formed of diverging cells. 
Genus 1. CALOMENA. 
The frond coriaceous, flabellate, imbricate at the base, formed of a 
succession of single elongated cylindrical cells which separate at 
the tip into two or rarely three similar cells, and forming a suc- 
cession of forked (rarely at the lower part of the frond trifid) branches 
to.the margin of the frond; the cells diminishing in length as 
they approach the margin; the interspaces between the cells mi- 
nutely cellular. 
This genus is most distinct from Anadyomene. It is like the fur- 
cately-branched Valonia, called Ascothamnion, expanded and united 
together into a frond, but the disk of the frond shows none of the 
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