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574 University of California Publications in Botany [Vol.8
at wide angles with the primary branches; color light brown; zoo-
sporangia unknown; cortical filaments short, composed of 2-3 cells
with a subspherical terminal cell.
Growing in abundance on stones. West shore of Amaknak Island,
Unalaska, Alaska.
Setchell and Gardner, Phyc. Cont., 1924, p. 8.
The slender percurrent axis bearing numerous short, almost equal,
lateral branches over most of its length with short branchlets and all
axes patent to one another, give the plants of the single collection
available a very distinctive appearance. The plants are young and
sterile, but the structure of the frond, the terminal subapical growth
and the discoid holdfast indicate its affinities with Chord-aria. In the
Algae of Northwest America (1903, p. 248) we placed this plant
under Dictyosiphon foenicidaeeus (Huds.) Grew, an untenable posi-
tion, since the subterminal growth and other details of structure plainly
show its different nature.
3. Chordaria dissessa S. and G.
Plate 41, fig. 57, and plate 75
Fronds attached by a small disk, 15-25 cm. high, up to 2 mm. thick,
moderately and alternately branched, usually wider at the branching,
but swollen in some parts and contracted in others, older parts at
times fistulous, olive brown in color, composed of a medulla of longi-
tudinal filaments giving rise to a cortex of short assimilating filaments
filaments of the medulla composed of large, colorless, closely compact,
thick-walled cells up to 120/x diam. in the central part of the frond,
many times longer than the diameter, becoming much shorter and
narrower toward the periphery ; cortical erect filaments cylindrical,
simple or branched, not closely compact, 4-6^, diam., composed of 2-4
cells, terminal cell swollen and globular ; hairs unknown ; branches of
each different order reduced in size, terminal ramuli long-attenuate
and acute, angles mostly wide and rounded ;
ellipsoidal, 36-42^ long, 28-32/* broad ;
zoosporangia obovoid to
gametangia unknown.
Growing on eel grass in the middle and lower littoral belts. East
Sound, Orcas Island, Washington.
Setchell and Gardner, Phyc. Cont., 1924, p. 8. Castagnea divari-
cata Setchell and Gardner, Alg. N.W. Amer., 1903, p. 249 (not C.
(firaricata (Ag.) J. Ag.).
The resemblance between Chardaria dissessa and C. divaricata
(Ag.) Grev. is superficially close, but the former has its main axes less
;