65 
ON ANADYOMENE AND MICRODICTYON, WITH THE 
DESCRIPTION OF THREE NEW ALLIED GENERA, DIS- 
COVERED BY MENZIES IN THE GULF OF MEXICO. 
By Dr. J. E. Gray, ERS- V.P.Z.S., FES: 
(Concluded from p. 51.) 
(Prats XLIV.) 
Group II. MICRODICTYONEMEÆ.— Frond reticulated, formed of 
a number of regularly-disposed anastomosing cells, leaving 
four-sided apertures between them, each side being formed of a 
single cell; the main filament articulated, each joint throwing 
out opposite branches at right angles to each other, which are 
similarly branched ; the cells containing endochrome. 
I have already stated that I believe this group to be nearly related to 
Cladophora among the Confervacee. 
The filiform stem and the filiform axis or midrib of the frond in both 
genera give off opposite branches ; the midrib and its branches in the 
frond give off cells on each side, placed opposite each other on the 
sides of the stalk, and the spaces between these cells are filled up 
with cells like those of which the joints of the filament are composed, 
making the whole frond into a beautiful net with polygonal open 
meshes, 
M. Montagne figured .4. Calodictyon on t. 8. f. 1 of Webb and 
Berthelot’s work, 1850. He observes, “La couleur et la nature des 
filaments articulés et anastomosós qui forment toute cette algue ont 
beaucoup d'analogie avec celles des filaments de la Conferva prolifera sje 
vois quelque analogie iu ce genre et le genre Flabellaria, Lamx., que je 
crois trés-bon à a conserver." M. Montagne figured a central part of the 
Alga, and also a part near the circumference of the frond, s showing that 
the terminal ramifications are free, forming “un bord déchiqueté et 
frangé,” gradually anastomosing ups it; see t. 8. f. 1. c, c" 
e group consists of two genera 
Genus 1. Microprceryon. =+Froad Josie lage orlobed, and pro- 
liferous, attached by a subcentral disk; the main filament radiating 
from centre to centre. 
Genus 2. PuvrLopicrYoN.—Frond oblong, free, ms from a 
VOL. IV. [MARCH 1, 1866.] — 
