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 DICTYOSIPHONACEJE 

 GENUS Dictyosiphon 



D. foeniculaceus. Fronds filiform, bristle-like, branching into deli- 

 cate, hair-like branches ; yellowish-brown. It resembles Chordaria flagel- 

 liformis, but is much finer. (Plate XI.) 



ORDER ELACHISTACEJE 

 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 CHORD ARI ACE JE 



C" Cord-like ") 



GENUS Chordaria 



C. flagettiformis ("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.) 



