OLIVE-GREEN AND BROWN SEAWEEDS 67 
grows from one foot to six feet in length, below low-water mark, and is 
found washed ashore. It is an attractive plant in the spring, but is brown 
and coarse when old. Common everywhere. (Plate X.) 
D. ligulata. Fronds two to six feet long, pinnate, having a flat main 
stem one half of an inch or more wide, with opposite flat branches; leaf- 
lets arranged along the edges of the branches, pointed at each end, and 
bordered with forward-pointing spines. It is found washed ashore, in 
abundance, in California, but is not found on the Atlantic coast. 
(Plate X.) 
Genus Arthrocladia 
A. villosa. Olive-brown filaments, resembling fine, knotted threads, 
each knob having a whorl of delicate filaments. It grows from six inches 
to three feet long, in deep water. It is rare, but is occasionally found on 
the New England coast. 
ORDER DICTYOSIPHONACEE 
Genus Dictyosiphon 
D. feeniculaceus. Fronds filiform, bristle-like, branching into deli- 
eate, hair-like branches; yellowish-brown. It resembles Chordaria flagel- 
liformis, but is much finer. (Plate XI.) 
ORDER ELACHISTACEZ 
Genus Elachista 
The plants of this genus are small, olive-colored, unbranched, 
hair-like filaments, growing in dense, radiating tufts, one half of 
an inch in height, on Fucus. They are interesting to the micro- 
scopist, but not to the collector. 
ORDER CHORDARIACEZ 
(“ Oord-like") 
Genus Chordaria 
C. flageliformis (‘ whip-like”). Firm, leathery, somewhat elastic, 
‘slimy strings, six to twenty-four inches long, and twice as thick as a 
bristle ; branches mostly undivided, short or long, irregularly placed on 
the main axis, and curving inward at the top of the frond; main axis 
not extending as far as the branches; blackish in color; attached by a 
disk to stones and shells; solitary or in bunches. It is common along 
the New England coast. (Plate XI.) 
